MRKELEY 

USRARY 


EARTH 


THE 


"GLACIERS 

UP.T  vr: 


V,A 
Jl 


NARRATIVE  OP  EXCURSIONS  AND  'ASCENTS, 


A 


THE  ORIGIN  AND  PHENOMENA  OF  GLACIERS, 


AX   EXPOSITION  OF   THE   PHYSICAL   PRINCIPLES   TO 
WHICH  THEY  ARE  RELATED. 


BY  JOHN  TYNDALL,  F.R.S., 

MEMBER    OF    THE    ROYAL    SOCIETIES    OF    SCIENCE    OF    HOLLAND    AND    GOTTINGEN  ;     Oi 

THE  SCIENTIFIC    SOCIETIES    OF    HALLE,    MARBURG,    AND    ZURICH  ;    OF    THE    SOCIETK 

PHILOMATIQUE  OF   PARIS  j    OF  THE  NATURAL  HISTORY  AND  PHYSICAL  SOCIETY 

OF    GENEVA  ;    OF    THE    PHYSICAL    SOCIETY    OF    BERLIN  ; 

PROFESSOR   OF   NATURAL   PHILOSOPHY  IN    THE    ROYAL    INSTITUTION   OF  GREAT    BRITAIN, 
AND   IN    THE    GOVERNMENT    SCHOOL    OF    MINES. 


JUUstratfons. 


BOSTON: 
TICK  NOR     AND     FIELDS 

M  DCCC  LXI. 


EARTH 

SCIENCES 

LIBRARY 


AUTHOR'S    EDITION 

<©"")• 


University  Press,  Cambridge: 
Printed  by  Welch,  Bigelow,  and  Company. 


TO 


M  I  CHAEL    F  AK  AD  A  Y, 


THIS    BOOK 


IS  AFFECTIONATELY  INSCRIBED. 


1860. 


PREFACE. 


IN  the  following  work  I  have  not  attempted  to  mix 
Narrative  and  Science,  believing  that  the  mind  once 
interested  in  the  one,  cannot  with  satisfaction  pass  ab- 
ruptly to  the  other.  The  book  is  therefore  divided 
into  Two  Parts :  the  first  chiefly  narrative,  and  the 
second  chiefly  scientific. 

In  Part  I.  I  have  sought  to  convey  some  notion  of 
the  life  of  an  Alpine  explorer,  and  of  the  means  by 
which  his  knowledge  is  acquired.  In  Part  II.  an  at- 
tempt is  made  to  classify  such  knowledge,  and  to  refer 
the  observed  phenomena  to  their  physical  causes. 

The  Second  Part  of  the  work  is  written  with  a  desire 
to  interest  intelligent  persons  who  may  not  possess  any 
special  scientific  culture.  For  their  sakes  I  have  dwelt 
more  fully  on  principles  than  I  should  have  done  in 
presence  of  a  purely  scientific  audience.  The  brief 
sketch  of  the  nature  of  Light  and  Heat,  with  which 
Part  II.  is  commenced,  will  not,  I  trust,  prove  unin- 
teresting to  the  reader  for  whom  it  is  more  especially 
designed. 


VI  PKEFACE. 

Should  any  obscurity  exist  as  to  the  meaning  of  the 
terms  Structure,  Dirt-bands,  Regelation,  Interference, 
and  others  which  occur  in  Part  I.,  it  will  entirely  dis- 
appear in  the  perusal  of  Part  II. 

Two  ascents  of  Mont  Blanc  and  two  of  Monte  Rosa 
are  recorded ;  but  the  aspects  of  nature,  and  other 
circumstances  which  attracted  my  attention,  were  so 
different  in  the  respective  cases,  that  repetition  was 
scarcely  possible. 

The  numerous  interesting  articles  on  glaciers  which 
have  been  published  during  the  last  eighteen  months, 
and  the  various  lively  discussions  to  which  the  subject 
has  given  birth,  have  induced  me  to  make  myself  better 
acquainted  than  I  had  previously  been  with  the  historic 
aspect  of  the  question.  In  some  important  cases  I  have 
stated,  with  the  utmost  possible  brevity,  the  results  of 
my  reading,  and  thus,  I  trust,  contributed  to  the  for- 
mation of  a  just  estimate  of  men  whose  labours  in  this 
field  were  long  anterior  to  my  own. 

J.  T. 

Royal  Institution,  June,  1860. 


CONTENTS. 

PART    I. 

1.    INTRODUCTORY. 

PAGE 

Visit  to  Penrhyn ;  the  Cleavage  of  Slate  Rocks  ;  Sedgwick's  Theory  — 
its  Difficulties;  Sharpe's  Observations;  Sorby's  Experiments;  Lec- 
ture at  the  Royal  Institution  ;  Glacier  Lamination  ;  Arrangement  of 
an  Expedition  to  Switzerland 1 

2.     EXPEDITION  OF  1856:   THE  OBERLAND. 

Valley  of  Lauterbrunnen  ;  Pliability  of  Rocks ;  the  Wengern  Alp  ;  the 
Jungfrau  and  Silberhorn;  Ice  Avalanches;  Glaciers  formed  from 
them ;  Scene  from  the  Little  Scheideck ;  the  Lower  Grindelwald  Gla- 
cier ;  the  Heisse  Platte  —  its  Avalanches  ;  Ice  Minarets  and  Blocks  ; 
Echos  of  the  Wetterhorn ;  Analogy  with  the  Reflection  of  Light  from 
Angular  Mirrors ;  the  Reichenbach>  Cascade ;  Handeck  Fall ;  the 
Grimsel ;  the  Unteraar  Glacier ;  Hut  of  M.  Dolfuss ;  Hotel  des  Neuf- 
chatelois ;  the  Rhone  Glacier  from  the  Mayenwand ;  Expedition  up 
the  Glacier;  Coloured  Rings  round  the  Sun;  Crevasses  of  the  Ne'vtf ; 
Extraordinary  Meteorological  Phenomenon ;  Spirit  of  the  Brocken  .  9 

3.     THE  TYROL. 

Kaunserthal  and  the  Gebatsch  Alp ;  Senner  or  Cheesemakers ;  Gebatsch 
Glacier ;  a  Night  in  a  Cow-shed ;  Passage  to  Lantaufer ;  a  Chamois 
on  the  Rocks ;  my  Guide ;  the  Atmospheric  Snow-line ;  Passage  of 
the  Stelvio ;  Colour  of  fresh  Snow ;  Bormio ;  the  Pass  recrossed  by 
Night;  Aspect  of  the  Mountains;  Meran  toUnserfrau;  Passage  of 
the  Hochjoch  to  Fend ;  Singular  Hailstorm  ;  Wild  Glacier  Region ; 
Hidden  Crevasses ;  First  Paper  presented  to  the  Royal  Society  .  23 

4.    EXPEDITION  OF  1857:  THE  LAKE  OF  GENEVA. 

Blueness  of  the  Water;  the  Head  of  the  Lake;  Appearance •  of  the 
Rhone ;  Subsidence  of  Particles  ;  Mirage 33 


viii  CONTENTS. 

5.    CHAMOUNI  AND  THE  MONTANVERT. 

Arrival;  Coloured  Shadows  on  the  Snow ;  Source  of  the  Arveiron ;  Fall 
of  the  Vault ;  "  Sunrise  in  the  Valley  of  Chamouni ; "  Scratched 
Rocks;  Quarters  at  the  Montanvert 37 

6.     THE  MER  DE  GLACE. 

Not  a  Sea  but  a  River  of  Ice ;  Wave-forms  on  its  Surface ;  their  Expla- 
nation ;  Structure  and  Strata ;  Glacier  Tables ;  First  View  of  the  Dirt 
Bands ;  Influence  of  Illumination  in  rendering  them  visible ;  the  Eye 
incapable  of  detecting  Differences  between  intense  Lights  .  .42 

7. 

Measurements  commenced;  the  "Cleft  Station"  at  Trelaporte ;  Rege- 
lation  of  Snow  Granules ;  two  Chamois ;  View  of  the  Mer  de  Glace 
and  its  Tributaries ;  Se'racs  of  the  Col  du  Geant ;  Sliding  and  Viscous 
Theories;  Rending  of  the  Ice ;  Striae  on  its  Surface ;  White  Ice-seams  46 

8. 

Alone  upon  the  Glacier ;  Lakes  and  Rivulets ;  Parallel  between  Glacier 
and  Geological  Disturbance ;  Splendid  Rainbow  ;  Aspect  of  the  Gla- 
cier at  the  Base  of  the  Seracs ;  Visit  to  the  Chief  Guide  at  Chamou- 
ni; Liberties  granted .57 


9.    THE*  JARDIN. 

Glacier  du  Talefre ;  Jardin  divides  the  Neve ;  Blue  Veins  near  the  Sum- 
mit ;  Surrounding  Scene ;  Moraines  and  Avalanches ;  Cascade  du 
Talefre ;  Dangers  on  approaching  it  from  above  .  .  .  .61 

10. 

Lightning  and  Rain ;  Spherical  Hailstones ;  an  Evening  among  the  Cre- 
vasses ;  Dangerous  Leap ;  Ice-Practice ;  Preparations  for  an  Ascent 
of  Mont  Blanc 64 

11.    FIRST  ASCENT  OF  MONT  BLANC,  1857. 

Across  the  Mountain  to  the  Glacier  des  Bossons ;  its  Crevasses  ;  Ladder 
left  behind  ;  Consequent  Difficulties ;  the  Grands  Mulcts ;  Twinkling 
and  Change  of  Colour  of  the  Stars ;  Moonlight  on  the  Mountains  ;  start 
with  one  Guide ;  Difficulties  among  the  Crevasses ;  the  Petit  Plateau ; 
Seracs  of  the  Dome  du  Goute  ;  Bad  Condition  of  Snow ;  the  Grand 
Plateau ;  Coloured  Spectra  round  the  Sun ;  the  lost  Guides ;  the  Route 


CONTENTS.  ix 

missed ;  Dangerous  Ice-Slope ;  Guide  exhausted  ;  Cutting  Steps  ; 
Cheerless  Prospect ;  the  Corridor ;  the  Mur  de  la  Cote ;  the  Petits  Mu- 
lcts ;  Food  and  Drink  disappear ;  Physiological  Experiences  on  the 
Calotte  ;  Summit  attained ;  the  Clouds  and  Mountains ;  Experiment 
on  Sound ;  Colour  of  the  Snow ;  the  Descent ;  a  solitary  Prisoner ; 
Second  Night  at  the  Grands  Mulets  ;  Inflammation  of  Eyes  ;  a  Blind 
Man  among  the  Crevasses ;  Descent  to  Chamouni ;  Thunder  on  Mont 
Blanc 68 

12. 

Life  at  the  Montanvert ;  Glacier  "  Blower ; "  Cascade  of  the  Talefre ; 
Difficulties  in  setting  out  Lines  ;  Departure  from  the  Montanvert ;  my 
Hosts ;  Prospect  from  the  Glacier  des  Bois ;  Edouard  Simond  .  86 

13.    EXPEDITION  OF  1858. 
Origin  and  Aim  of  the  Expedition;  Laminated  Structure  of  the  Ice     .     92 

14.    PASSAGE  OF  THE  STRAHLECK. 

Unpromising  Weather ;  Appearance  of  the  Glacier  and  of  the  adja- 
cent Mountains ;  Transverse  Protuberances ;  Dirt  Bands ;  Structure ; 
a  Slip  on  a  Snow  Slope ;  the  Finsteraarhorn;  the  Schreckhorn ;  Ex- 
traordinary Atmospheric  Effects  ;  Summit  of  the  Strahleck  ;  Grand 
Amphitheatre ;  Mutations  of  the  Clouds ;  Descent  of  the  Rocks  ;  a 
Bergschrund ;  Fog  in  the  Valley ;  Descent  to  the  Grimsel  .  .  93 

15. 

Ancient  Glaciers  in  the  Valley  of  Hasli;  Rounded,  Polished,  and  Stri- 
ated Rocks ;  Level  of  the  Ancient  Ice ;  Groovings  on  the  Grimsel 
Pass ;  Glacier  of  the  Rhone  ;  Descent  of  the  Rhone  Valley ;  the  JEg- 
-gischhorn;  Cloud  Iridescences;  the  Aletsch  Glacier;  the  Margelin 
See ;  Icebergs ;  Tributaries  of  the  Aletsch  ;  Grand  Glacier-region ; 
Crevasses ;  a  Chamois  deceived 99 

16.    ASCENT  OF  THE  FINSTERAARHORN. 

Character  of  my  Guide ;  Iridescent  Cloud  ;  Evening  on  the  Faulberg ; 
the  Jungfrau  and  her  Neighbours ;  a  Mountain  Gave ;  the  Jungfrau 
before  Dawn ;  Contemplated  Visit ;  the  Griinhorn  Liicke ;  Magnifi- 
cent Corridor ;  Sunrise ;  Ne've'  of  the  Viesch  Glacier ;  Halt  at  the 
Base  of  the  Finsteraarhorn  ;  Spurs  and  Couloirs  of  the  Mountain  ; 
Pyramidal  Crest;  Scene  of  Agassiz's  Observations;  a  Hard  Climb; 


X  CONTENTS. 

Discipline  of  such  an  Ascent  ;  Boiling  Point  ;  Registering  Thermom- 
eter, its  Fate  ;  Daring  Utterance  ;  Descent  by  Glissades  ;  the  Viesch 
Glacier  ;  Hidden  Crevasses  ;  a  Brave  and  Competent  Guide  .  .104 

17. 

Subsequent  Days  at  the  JEggischhorn  ;  Afloat  on  the  Icebergs  ;  Bed- 
ding and  Structure  ;  Ancient  Moraines  of  the  Aletsch  ;  Scratched 
Rocks  ;  Passage  of  the  Mountains  to  the  end  of  the  Glacier  ;  a  wild 
Gorge  ;  Arrival  at  Zermatt  ;  the  Riffelberg  .....  119 

18.    FIRST  ASCENT  OF  MONTE  ROSA,  1858. 

The  Ascent  new  to  myself  and  my  Guide  ;  Directions  ;  Ulrich  Laue- 
ner  ;  Ominous  Clouds  ;  Passage  of  the  Gorner  Glacier  ;  Roches  Mou- 
tonnees  ;  Avalanche  from  the  Twins  ;  Gradual  Advance  of  Clouds  ; 
Bridged  Chasms  ;  Scene  from  a  Cliff;  Apparent  Atmospheric  Strug- 
gle ;  Sound  of  the  Snow  ;  Dangerous  Edge  ;  Overhanging  Cornice  ; 
Staff  driven  through  it;  Increased  Obscurity;  Rocky  Crest;  Loss 
of  Pocketbook  ;  Summit  attained  ;  Boiling  Point  ;  Fall  of  Snow  ; 
Exquisite  Forms  of  the  Snow  Crystals  ;  a  Shower  of  Frozen  Blos- 
soms ;  the  Descent  ;  Mode  of  Attachment  ;  Startling  Avalanche  ; 
Blue  Light  emitted  from  the  Fissures  of  the  fresh  Snow  ;  Stifling 
Heat  ;  Return  to  the  Riffel  ........  122 


The  Rothe  Kumm  ;  Pleasant  Companions  ;  Difficult  Descent  ;  Tem- 
peratures of  Rock,  Air,  and  Grass  ;  Singular  Cavern  in  the  Ice  ; 
Structure  and  Stratification  ......  .  .133 

20.    THE  GORNER  GRAT  AND  THE  RIFFELHORN. 
MAGNETIC  PHENOMENA. 

Formation  and  Dissipation  of  Clouds  ;  Scene  from  the  Gorner  Grat  ; 
Magnetism  of  the  Rocks  ;  the  Compass  and  Sun  at  Variance  ;  As- 
cent of  the  Riffelhorn  ;  Magnetic  Effects  ;  Places  of  most  intense 
Action  ;  Scratched  and  Polished  Rocks  ;  Exfoliation  of  Crust  pro- 
duced by  the  Sliding  of  Ancient  Glaciers  ;  Magnetic  Polarity  ;  Con- 
sequent Points  ;  Bearings  from  the  Riffelhorn  ;  Action  on  a  distant 
Needle  ............  137 

21. 

Fog  on  the  Riffelberg  ;  its  Dissipation  ;  Sunset  from  the  Gorner  Grat  ; 
Cloud-wreaths  on  the  Matterhorn  ;  Streamers  of  Flame  ;  Grand  In- 


CONTENTS.  xi 

terference  Phenomenon  ;  Investigation  of  Structure  ;  the  Gornerhorn 
Glacier ;  Western  Glacier  of  Monte  Rosa  ;  the  Schwartze,  Trifti,  and 
Theodule  Glaciers ;  Welding  of  the  Tributaries  to  Parallel  Strips  ; 
Temptation 145 

22.    SECOND  ASCENT  OF  MONTE  ROSA,  1858. 

A  Light  Scrip  ;  my  Guide  lent ;  a  Substitute  ;  a  Party  on  the  Moun- 
tain ;  across  the  Glacier  and  up  the  Rocks  ;  the  Guide  expostulates  ; 
among  the  Crevasses ;  the  Guide  halts ;  left  alone ;  Beauty  of  the 
Mountain  ;  Splendid  Effects  of  Diffraction ;  Cheer  from  the  Summit ; 
on  the  Kamm ;  Climbers  meet ;  among  the  Rocks ;  alone  on  the 
Summit ;  the  Axe  slips ;  the  Prospect ;  the  Descent ;  Serious  Acci- 
dent; a  Word  on  Climbing  alone 151 

23. 

The  Furgge  Glacier ;  Thunder  and  Lightning ;  the  Weissthor  given 
up ;  Excursion  by  Stalden  to  Saas ;  Herr  Imseng ;  the  Mattmark 
See  and  Hotel ;  Ascent  of  a  Boulder  ;  Snow-storm  ;  Cold  Quarters ; 
the  Monte  Moro  ;  the  Allelein  Glacier ;  a  Noble  Vault ;  Structure 
and  Dirt-bands;  Stormy  Weather;  Avalanches  at  Saas;  the  Fe'e 
Glacier ;  Frozen  Dust  on  the  Mischabelhorner ;  Snow,  Vapour,  and 
Cloud ;  Curious  Effect  on  the  Hearing ;  "  a  Terrible  Hole  ;  "  Singu- 
lar Group  ;  a  Song  from  the  "  Robbers  " 160 

24. 

Need  of  Observations  on  Alpine  Temperature ;  Balmat's  Intention  ; 
Aid  from  the  Royal  Society  ;  Difficulties  at  Chamouni  in  1858  ;  the 
Intendant  memorialized  ;  his  Response ;  the  Se'racs  revisited ;  Cre- 
vasses and  Crumples;  Bad  Weather;  Thermometers  placed  at  the 
Jardin  ;  Avalanches  of  the  Talefre  ;  Wondrous  Sky  .  .  .168 

25.    SECOND  ASCENT  OF  MONT  BLANC,  1858. 

Shadows  of  the  Aiguilles  ;  Silver  Trees  at  Sunrise  ;  M.  Necker's  Let- 
ter ;  Birds  as  Sparks  and  Stars  against  the  Sky  ;  Crevasse  bridged  ; 
Ladder  rejected ;  a  Hunt  for  a  Pont ;  Crevasses  crossed ;  Magnifi- 
cent Sunset ;  Illuminated  Clouds  ;  Storm  on  the  Grands  Mulcts ;  a 
Comet  discovered ;  Start  by  Starlight;  the  Petit  Plateau  a  Reservoir 
for  Avalanches  ;  Balmat's  Warning ;  the  Grand  Plateau  at  Dawn  ; 
Blue  of  the  Ice  ;  Balmat  in  Danger ;  Clouds  upon  the  Calotte  ;  the 
Summit ;  Wind  and  Snow-dust ;  Balmat  Frostbitten ;  Halt  on  the 
Calotte;  Descent  to  Chamouni ;  Good  Conduct  of  Porters  .  .  177 


Xll  CONTENTS. 

26. 

Hostility  of  Chief  Guide;  Proces  Verbal;  the  British  Association; 
Application  to  the  Sardinian  Authorities  ;  President's  Letter ;  Royal 
Society;  Testimonial  to  Balmat 192 

27.    WINTER  EXPEDITION  TO  THE  MER  DE  GLACE,  1859. 

First  Defeat  and  fresh  Attempt ;  Geneva  to  Chamouni ;  Deep  Snow  ; 
Desolation ;  Slow  Progress ;  a  Horse  in  the  Snow ;  a  Struggle  ;  Cha- 
mouni on  Christmas  Night ;  Mountains  hidden ;  Climb  to  the  Mon- 
tanvert;  Snow  on  the  Pines;  Debris  of  Avalanches ;  Breaking  of 
Snow;  Atmospheric  Changes;  the  Mountains  concealed  and  re- 
vealed ;  Colour  of  the  Snow ;  the  Montanvert  in  Winter ;  Footprints 
in  the  Snow;  Wonderful  Frost  Figures  ;  Crystal  Curtain  ;  the  Mer 
de  Glace  in  Winter  ;  the  First  Night ;  "  a  Rose  of  Dawn ; "  Crimson 
Banners  of  the  Aiguilles ;  the  Stakes  fixed ;  a  Hurricane  on  the 
Glacier ;  the  Second  Night ;  Wild  Snow-storm  ;  a  Man  in  a  Crevasse  ; 
Calm ;  Magnificent  Snow  Crystals ;  Sound  through  the  falling  Snow ; 
Swift  Descent ;  Source  of  the  Arveiron ;  Crystal  Cave ;  Appearance 
of  Water ;  Westward  from  the  Vault ;  Majestic  Scene ;  Farewell  .  195 


PART    II. 

1.    LIGHT  AND  HEAT. 

What  is  Light?  — Notion  of  the  Ancients;  requires  Time  to  pass 
through  Space ;  Romer,  Bradley,  Fizeau ;  Emission  Theory  support- 
ed by  Newton,  opposed  by  Huyghens  ;  the  Wave  Theory  established 
by  Young  and  Fresnel ;  Theory  explained  ;  Nature  of  Sound ;  of 
Music ;  of  Pitch  ;  Nature  of  Light ;  of  Colour ;  two  Sounds  may  pro- 
duce Silence ;  two  Rays  of  Light  may  produce  Darkness  ;  two  Rays 
of  Heat  may  produce  Cold  ;  Length  and  Number  of  Waves  of  Light ; 
Liquid  Waves  ;  Interference  ;  Diffraction  ;  Colours  of  Thin  Plates  ; 
Applications  of  the  foregoing  to  Cloud  Iridescences,  Luminous  Trees, 
Twinkling  of  Stars,  the  Spirit  of  the  Brocken,  &c.  . .  .  .  223 

2.    RADIANT  HEAT. 

The  Sun  emits  a  Multitude  of  Non-luminous  Rays ;  Rays  of  Heat  dif- 
fer from  rays  of  Light  as  one  Colour  differs  from  another ;  the  same 
Ray  may  produce  the  Sensations  of  Light  and  Heat  .  .  .239 


CONTENTS.  xiii 

3.     QUALITIES  OF  HEAT. 

Heat  a  Kind  of  Motion  ;  System  of  Exchanges ;  Luminous  and  Obscure 
Heat ;  Absorption  by  Gases ;  Gases  may  be.transparent  to  Light,  but 
opaque  to  Heat ;  Heat  selected  from  Luminous  Sources ;  the  Atmos- 
phere acts  the  part  of  a  Eatchet-wheel ;  Possible  Heat  of  a  Distant 
Planet;  Causes  of  Cold  in  the  upper  Strata  of  the  Earth's  Atmos- 
phere   241 

4.     ORIGIN  or  GLACIERS. 

Application  of  Principles ;  the  Snow-line ;  its  Meaning  ;  Waters  piled 
annually  in  a  solid  Form  on  the  Summits  of  the  Hills  ;  the  Glaciers 
furnish  the  chief  Means  of  Escape ;  Superior  and  Inferior  Snow-line  248 


5. 

Whiteness  of  Snow ;  Whiteness  of  Ice ;  Round  Air-bubbles  ;  Melting 
and  Freezing  ;  Conversion  of  Snow  into  Ice  by  Pressure  .  .  249 

6.     COLOUR  OF  WATER  AND  ICE. 

Waves  of  Ether  not  entangled ;  they  are  separated  in  the  Prism  ;  they 
are  differently  absorbed  ;  Colour  due  to  this  ;  Water  and  Ice  Blue ; 
Water  and  Ice  opaque  to  Radiant  Heat ;  Long  Waves  shivered  on  the 
Molecules;  Experiment;  Grotto  of  Capri ;  the  Laugs  of  Iceland  .  25.'] 

7.     COLOURS  OF  THE  SKY. 

Newton's  Idea ;  Goethe's  Theory ;  Clausius  and  Briicke ;  Suspended 
Particles ;  Singular  Effect  on  a  Painting  explained  by  Goethe  ;  Light 
separated  without  Absorption;  Reflected  and  Transmitted  Light; 
Blueness  of  Milk  and  Juices ;  the  Sun  through  London  Smoke ;  Ex- 
periments ;  Blue  of  the  Eye ;  Colours  of  Steam ;  the  Lake  of  Ge- 
neva  257 

8.    THE  MORAINES. 

Glacier  loaded  along  its  Edges  by  the  Ruins  of  the  Mountains  ;  Lateral 
Moraines  ;  Medial  Moraines  ;  their  Number  one  less  than  the  Num- 
ber of  Tributaries  ;  Moraines  of  the  Mer  de  Glace ;  Successive  Shrink- 
ings  ;  Glacier  Tables  explained;  "Dip"  of  Stones  upon  the  Glacier 
enables  us  to  draw  the  Meridian  Line ;  Type  "  Table ; "  Sand  Cones ; 
Morains  engulfed  and  disgorged ;  Transparency  of  Ice  under  the 
Moraines .  263 


XIV  CONTENTS. 

9.  GLACIER  MOTION-  —  PRELIMINARY. 

Neve  and  Glacier ;  First  Measurements  ;  Hugi  and  Agassiz ;  Escher's 
Defeat  on  the  Aletsch ;  Piles  fixed  across  the  Aar  Glacier  by  Agas- 
siz in  1841 ;  Professor  Forbes  invited  by  M.  Agassiz ;  Forbes's  First 
Observations  on  the  Mer  de  Glace  in  1842 ;  Motion  of  Agassiz's  Piles 
measured  by  M.  Wild ;  Centre  of  the  Glacier  moves  quickest ;  State 
of  the  Question 26S 

10.  MOTION  OF  THE  MER  DE  GLACE. 

The  Theodolite  ;  Mode  of  Measurement ;  First  Line;  Centre  Point  not 
the  quickest ;  Second  Line ;  Former  Result  confirmed ;  Law  of  Mo- 
tion sdught ;  the  Glacier  moves  through  a  Sinuous  Valley ;  Effect  of 
Flexure;  Western  Half  of  Glacier  moves  quickest ;  Point  of  Maxi- 
mum Motion  crosses  Axis  ;  Eastern  Half  moves  quickest ;  Locus  of 
Point  of  Maximum  Motion ;  New  Law ;  Motion  of  the  Geant ;  Mo- 
tion of  the  Lechaud  ;  Squeezing  of  the  Tributaries  through  the  Neck 
of  the  Valley  at  Tre'laporte ;  the  Lechaud  a  Driblet  .  .  .  27  £ 

11.     ICE- WALL  AT  THE  TACUL.  —  VELOCITIES  OF  TOP 
AND  BOTTOM. 

First  Attempt  by  Mr.  Hirst ;  Second  Attempt,  Stakes  fixed  at  Top,  Bot- 
tom, and  Centre ;  Dense  Fog ;  the  Stakes  lost ;  Process  repeated ; 
Velocities  determined 28? 

12.     WINTER  MOTION  OF  THE  MER  DE  GLACE. 

First  Line,  Above  the  Montanvert ;  Second  Line,  Below  the  Montan- 
vert ;  Ratio  of  Winter  to  Summer  Motion 294 

13.     CAUSE  OF  GLACIER  MOTION.  —  DE  SAUSSURE'S  THEORY. 

First  Attempt  at  a  Theory  by  Scheuchzer  in  1705 ;  Charpentier's  The- 
ory, or  the  Theory  of  Dilatation  ;  Agassiz's  Theory  ;  Altmann  and 
Griiner ;  Theory  of  De  Saussure,  or  the  Sliding  Theory ;  in  part 
true ;  Strained  interpretation  of  this  Theory 29f 

14.    REXDU'S  THEORY. 

Character  of  Rendu ;  his  Essay  entitled  "  Theorie  des  Glaciers  de  la 
Savoie;"  Extracts  from  the  Essay;  he  ascribes  "Circulation"  to 
Natural  Forces ;  Classifies  Glaciers ;  Assigns  the  Cause  of  the  Con- 
version of  Snow  into  Ice ;  Notices  Veined  Structure ;  "  Time  and 
Affinity;"  Notices  Regelation;  Diminution  of  Glaciers  Reservoirs; 


CONTENTS.  XV 

Remarkable  Passage  ;  announces  Swifter  Motion  of  Centre ;  North 
British  Review ;  Discrepancies  explained  by  Rendu ;  Liquid  Motion 
ascribed  to  Glacier ;  all  the  Phenomena  of  a  River  reproduced  upon 
the  Mer  de  Glace ;  Ratio  of  Side  and  Central  Velocities ;  Errors 
removed 299 

15. 

Anticipations  of  Rendu  confirmed  by  Agassiz  and  Forbes  ;  Analogies 
with  Liquid  Motion  established  by  Forbes ;  his  Measurements  in 
1842;  Measurements  in  1844  and  1846;  Measurements  of  Agassiz 
and  Wild  in  1842,  1843,  1844,  and  1845;  Agassiz  notices  the  "Mi- 
gration" of  the  Point  of  Swiftest  Motion  ;  true  Meaning  of  this  Ob- 
servation ;  Summary  of  Contributions  on  this  Part  of  the  Question  308 

16.    FORBES'S  THEORY. 

Discussions  as  to  its  Meaning ;  Facts  and  Principles  ;  Definition  of  The- 
ory ;  some  Experiments  on  the  Mer  de  Glace  to  test  the  Viscosity  of 
the  Ice 311 

17.    THE  CREVASSES. 

Caused  by  the  Motion ;  Ice  Sculpture ;  Fantastic  Figures ;  Beauty  of 
tbe  Crevasses  of  the  Higher  Glaciers  ;  Birth  of  a  Crevasse  ;  Me- 
chanical Origin ;  Line  of  greatest  Strain  ;  Marginal  Crevasses  ; 
Transverse  Crevasses ;  Longitudinal  Crevasses  ;  Bergschrunds ;  In- 
fluence of  Flexure ;  why  the  Convex  Sides  of  Glaciers  are  most 
crevassed 315 

18. 

Further  Considerations  on  Viscosity ;  Numerical  Test ;  Formation  of 
Crevasses  opposed  to  Viscosity 325 

19.    HEAT  AND  WORK. 

Connexion  of  Natural  Forces ;  Equivalence  of  Heat  and  Work ;  Heat 
produced  by  Mechanical  Action  ;  Heat  consumed  in  producing 
Work  ;  Chemical  Attractions ;  Attraction  of  Gravitation ;  Amount 
of  Heat  which  would  be  produced  by  the  Stoppage  of  the  Earth  in 
its  Orbit ;  amount  produced  by  the  Falling  of  the  Earth  into  the  Sun ; 
Shifting  of  Atoms  ;  Heat  consumed  in  Molecular  Work ;  Specific 
Heat  j  Latent  Heat ;  "  Friability  "  of  Ice  near  its  Melting  Point ; 
Rotten  Ice  and  Softened  Wax 328 

b 


xvi  CONTENTS. 

20. 

Papers  presented  to  the  Royal  Society  by  Professor  Forbes  in  1846 ; 
Capillary  Hypothesis  of  Glacier  Motion  ;  Hypothesis  examined  .  334 

21.    THOMSON'S   THEORY. 

Statement  of  Theory ;  Influence  of  Pressure  on  the  Melting  Point  of 
Ice ;  Difficulties  of  Theory ;  Calculation  of  Requisite  Pressure ; 
Actual  Pressure  Insufficient 340 

22.    PRESSURE  THEORY. 

Pressure  and  Tension ;  Possible  Experiments ;  Ice  may  be  moulded 
into  Vases  and  Statuettes,  or  coiled  into  Knots ;  this  no  Proof  of 
Viscosity;  Actual  Experiments;  a  Sphere  of  Ice  moulded  to  a 
Lens ;  a  Lens  moulded  to  a  Cylinder ;  a  Lump  of  Ice  moiilded  to  a 
Cup ;  Straight  Bars  of  Ice  bent ;  Ice  thus  moulded  incapable  of 
being  sensibly  stretched  ;  when  Tension  is  substituted  for  Pressure, 
Analogy  with  Viscous  Body  breaks  down 346 

23.    REGELATION. 

Faraday's  first  Experiments ;  Freezing  together  of  Pieces  of  Ice  at  32° ; 
Freezing  in  Hot  Water  ;  Faraday's  recent  Experiments  ;  Regelation 
not  due  to  Pressure  nor  to  Capillary  Attraction ;  it  takes  place  in 
Vacuo;  Fracture  and  Regelation ;  no  Viscidity  discovered  .  .  351 

24.     CRYSTALLIZATION  AND  INTERNAL  LIQUEFACTION. 

How  Crystals  are  "  nursed  ; "  Snow-Crystals ;  Crystal  Stars  formed 
in  Water ;  Arrangement  of  Atoms  of  Lake  Ice ;  Dissection  of  Ice 
by  a  Sunbeam  ;  Liquid  Flowers  formed  in  Ice ;  Associated  Vacuous 
Spots ;  Curious  Sounds ;  their  Explanation ;  Cohesion  of  Water 
when  Free  from  Air ;  Liquid  snaps  like  a  Broken  Spring ;  Ebulli- 
tion converted  into  Explosion ;  Noise  of  Crepitation ;  Water-cells 
in  Glacier  Ice ;  Vacuous  Spots  mistaken  for  Bubbles ;  not  Flattened 
by  Pressure ;  Experiments  ;  Cause  of  Regelation  ....  353 

25.     THE  MOULINS. 

Their  Character ;  Depth  of  Moulin  on  Grindelwald  Glacier ;  Explana- 
tion ;  the  Grand  Moulin  of  the  Mer  de  Glace ;  Motion  of  Moulins  .  362 


CONTENTS.  XV11 

26.    DIRT-BANDS  OF  THE  MER  DE  GLACE. 

Their  .Discovery  by  Professor  Forbes ;  View  of  Bands  from  a  Point 
near  the  Flegere  ;  Bands  as  seen  from  Les  Charmoz ;  Skew  Surface 
of  Glacier;  Aspect  of  Bands  from  the  Cleft  Station;  Origin  of 
Bands ;  Tendency  to  become  Straight ;  Differences  between  Ob- 
servers   367 

27.    VEINED  STRUCTURE  OF  GLACIERS. 

General  Appearance ;  Grooves  upon  the  Glacier ;  First  Observations  ; 
Description  by  M.  Guyot ;  Observations  of  Professor  Forbes  ;  Struc- 
ture and  Stratification  ;  Subject  examined  ;  Marginal  Structure  ; 
Transverse  Structure ;  Longitudinal  Structure ;  Experimental  Illus- 
trations ;  the  Structure  Complementary  to  the  Crevasses ;  Glaciers 
of  the  Oberland,  Valais,  and  Savoy  examined  with  reference  to  this 
Question 376 

28.    THE  VEINED  STRUCTURE  AND  DIFFERENTIAL  MOTION. 

Marginal  Structure  Oblique  to  Sides  ;  Drag  towards  the  Centre ;  Diffi- 
culties of  Theory  which  ascribes  the  Structure  to  Differential  Sliding ; 
it  persists  across  the  Lines  of  Maximum  Sliding  ....  395 

29.    THE  RIPPLE  THEORY  OF  THE  VEINED  STRUCTURE. 

Ripples  in  Water  supposed  to  correspond  to  Glacier  Structure ;  Ana- 
lysis of  Theory  ;  Observation  of  the  MM.  Weber  ;  Water  dropping 
from  an  Oar ;  Stream  cleft  by  an  Obstacle  ;  Two  Divergent  Lines 
of  Ripple ;  Single  Line  produced  by  Lateral  Obstacle  ;  Direction  of 
Ripples  compounded  of  River's  Motion  and  Wave  Motion  ;  Struc- 
ture and  Ripples  due  to  different  Causes ;  their  Positions  also  dif- 
ferent   398 

30.    THE  VEINED  STRUCTURE  AND  PRESSURE. 

Supposed  Case  of  Pressed  Prism  of  Glass ;  Experiments  of  Nature ; 
Quartz-Pebbles  flattened  and  indented ;  Pressure  would  produce 
Lamination;  Tangential  Action 404 

31.    THE  VEINED  STRUCTURE  AND  THE  LIQUEFACTION  OF 
ICE  BY  PRESSURE 

Influence  of  Pressure  on  Melting  and  Boiling  Points  ;  some  substances 
swell,  others  shrink  in  Melting;  Effects  of  Pressure  different  on 
both  Classes  of  Bodies ;  Theoretic  Anticipation  by  Mr.  James  Thom- 
son ;  Melting  Point  of  Ice  lowered  by  Pressure ;  Internal  Liquefac- 
tion of  a  Prism  of  Solid  Ice  by  Pressure  ;  Liquefaction  in  Layers ; 
Application  to  the  Veined  Structure 408 


xviii  CONTENTS. 

32.    WHITE  ICE-SEAMS  OF  THE  GLACIER  DU  GEANT. 

Aspect   of  Seams;    they  sweep  across    the  Glacier  concentric  with 
Structure ;  Structure  at  the  Base  of  the  Talefre  Cascade  ;  Crumples  ; " 
Scaling  off  by  Pressure ;  Origin  of  Seams  of  White  Ice  .        .        .    413 

33. 

Glacier  du  Geant  in  a  State  of  Longitudinal  Compression ;  Measure- 
ments which  prove  that  its  hinder  Parts  are  advancing  upon  those  in 
•Front ;    Shortening  of  its  Undulations ;   Squeezing  of  White  Ice- 
Seams  ;  Development  of  Veined  Structure        ....  419 

SUMMARY 422 

APPENDIX    .         .         .        .         .         .        .        .         .        .          427 

INDEX      .  .443 


ILLUSTRATIONS. 


THE  MER  DE  GLACE.  —  Showing  the  Cleft  Station  at  Tr&aporte,  the  Echelets, 

the  Tacul,  the  Pe'riades,  and  the  Grande  Jorasse      .        .        Frontispiece. 

FIG.  PAGE 

1.  Ice  Minaret .      14 

2.  Diagram  of  an  Angular  Reflector 16 

4*  j    Boats'  Sails  inverted  by  Atmospheric  Refraction        ....      35 

5.  Wave-like  Forms  on  the  Mer  de  Glace 43 

6.  Glacier  Table 44 

7.  Tributaries  of  the  Mer  de  Glace 53 

8.  Magnetic  Boulder  of  the  Riffelhorn .143 

9.1 

J'  I    Luminous  Trees  projected  against  the  Sky  at  Sunrise    .        .        180,  181 
12!  J 
13.  Snow  on  the  Pines 201 

'  |  Snow  Crystals 214 

16.  Chasing  produced  by  Waves 233 

17.  Diagram  explanatory  of  Interference 234 

19.  Moraines  of  the  Mer  de  Glace To  face  264 

20.  Typical  Section  of  a  Glacier  Table 266 

21.  Locus  of  the  Point  of  Maximum  Motion 286 

22.  Inclination  of  Ice  Cascade  of  the  Glacier  des  Bois       ....  313 

23.  Inclinations  of  Mer  de  Glace  above  F  Angle 314 

24.  Fantastic  Mass  of  Ice 316 

25.  Diagram  explanatory  of  the  Mechanical  Origin  of  Crevasses         .        .  318 


XX  ILLUSTRATIONS. 

WO.  PAGE 

26.  Diagram  showing  the  Line  of  Greatest  Strain 319 

27  B  I  Section  and  Plan  of  a  Potion  of  the  Lower  Grindelwald  Glacier      .  322 

28.  Diagram  illustrating  the  Crevassing  of  Convex  Sides  of  Glaciers        .  323 

29.  Diagram  illustrating  Test  of  Viscosity    .......  326 

30.1 
°i  I 
gM  Moulds  used  in  Experiments  with  Ice 346-348 

33!  j 

34.  Liquid  Flowers  in  Lake  Ice 355 

35.  Dirt-bands  of  the  Mer  de  Glace,  as  seen  from  a  Point  near  the  Flegere 

To  face  367 

36.  Ditto,  as  seen  from  Les  Charmoz "368 

37.  Ditto,  as  seen  from  the  Cleft  Station,  Tre'laporte         ..."       369 

38.  Plan  of  Dirt-bands  taken  from  Johnson's  "  Physical  Atlas  ".        .        .    374 

39.  Veined  Structure  on  the  Walls  of  Crevasses 381 

40.  Figure  explanatory  of  the  Marginal  Structure 383 

41.  Plan  of  part  of  Icefall,  and  of  Glacier  below  it  (Glacier  of  the  Rhone)        386 

42.  Section  of  ditto 386 

43.  Figure  explanatory  of  Longitudinal  Structure  ,  388 

44.  Structure  and  Bedding  on  the  Great  Aletsch  Glacier     .        .        .        .391 
*g'  j  Structure  and  Stratification  on  the  Furgge  Glacier  .        .        .        .        394 
47.  Diagram  illustrating  Differential  Motion          .        .        .        .     •  .        .395 

J  Diagrams  explanatory  of  the  Formation  of  Eipples  .        .        .         400,  403 

{?  J*  j  Appearance  of  a  Prism  of  Ice  partially  liquefied  by  Pressure  .  .  410 
j?g'  j  Figures  illustrative  of  Compression  and  Liquefaction  of  Ice  .  .  411 
jjg*  j  Sections  of  White  Ice-seams 414 

gj'  j  Variations  in  the  Dip  of  the  Veined  Structure          .        .        .         414,  415 

58.  Section  of  three  Glacier  Crumples 416 

59.  Wall  of  a  Crevasse,  with  Incipient  Crumpling 416 

60.  Plan  of  a  Stream  on  the  Glacier  du  Ge"ant 418 

61.  Plan  of  a  Seam  of  White  Ice  on  ditto 418 


PART    I. 

CHIEFLY    NARRATIVE 


Ages  are  your  days, 

Ye  grand  expressors  of  the  present  tense 

And  types  of  permanence  ; 

Firm  ensigns  of  the  fatal  Being 

Amid  these  coward  shapes  of  joy  and  grief 

That  will  not  bide  thee  seeing. 

Hither  we  bring 

Our  insect  miseries  to  the  rocks, 

And  the  whole  flight  with  pestering  wing 

Vanish  and  end  their  murmuring, 

Vanish  beside  these  dedicated  blocks. 

EMERSON. 


GLACIERS    OF   THE    ALPS. 


INTRODUCTORY. 


IN  the  autumn  of  1854  1  attended  the  meeting  of  the 
British  Association  at  Liverpool  ;  and,  after  it  was  over. 
availed  myself  of  my  position  to  make  an  excursion  into 
North  Wales.  Guided  by  a  friend  who  knew  the  country, 
I  became  acquainted  with  its  chief  beauties,  and  concluded 
the  expedition  by  a  visit  to  Bangor  and  the  neighbouring 
slate  quarries  of  Penrhyn. 

From  my  boyhood  I  had  been  accustomed  to  handle 
slates  ;  had  seen  them  used  as  roofing  materials,  and  had 
worked  the  usual  amount  of  arithmetic  upon  them  at 
school  ;  but  now,  as  I  saw  the  rocks  blasted,  the  broken 
masses  removed  to  the  sheds  surrounding  the  quarry,  and 
there  cloven  into  thin  plates,  a  new  interest  was  excited, 
and  I  could  not  help  asking  after  the  cause  of  this  extra- 
ordinary property  of  cleavage.  It  sufficed  to  strike  the 
point  of  an  iron  instrument  into  the  edge  of  a  plate  of  rock 
to  cause  the  mass  to  yield  and  open,  as  wood  opens  in 
advance  of  a  wedge  driven  into  it.  I  walked  round  the 
quarry  and  observed  that  the  planes  of  cleavage  were 
everywhere  parallel  ;  the  rock  was  capable  of  being  split 
in  one  direction  only,  and  this  direction  remained  perfectly 
constant  throughout  the  entire  quarry. 

I  was  puzzled,  and,  on  expressing  my  perplexity  to  my 
companion,  he  suggested  that  the  cleavage  was  nothing 
1 


2  CLEAVAGE  OF  SLATE  ROCKS. 

more  than  the  layers  in  which  the  rock  had  been  original- 
ly deposited,  and  which,  hy  some  subsequent  disturbance, 
had  been  set  on  end,  like  the  strata  of  the  sandstone  rocks 
and  chalk  cliffs  of  Alum  Bay.  But  though  I  was  too  igno- 
rant to  combat  this  notion  successfully,  it  by  no  means 
satisfied  me.  I  did  not  know  that  at  the  time  of  my  visit 
this  very  question  of  slaty  cleavage  was  exciting  the 
greatest  attention  among  English  geologists,  and  I  quitted 
the  place  with  that  feeling  of  intellectual  discontent  which, 
however  unpleasant  it  may  be  for  a  time,  is  very  useful  as 
a  stimulant,  and  perhaps  as  necessary  to  the  true  appre- 
ciation of  knowledge  as  a  healthy  appetite  is  to  the  enjoy- 
ment of  food. 

On  inquiry  I  found  that  the  subject  had  been  treated 
by  three  English  writers,  Professor  Sedgwick,  Mr.  Daniel 
Sharpe,  and  Mr.  Sorby.  From  Professor  Sedgwick  I 
learned  that  cleavage  and  stratification  were  things  totally 
distinct  from  each  other;  that  in  many  cases  the  strata 
could  be  observed  with  the  cleavage  passing  through  them 
at  a  high  angle  ;  and  that  this  was  the  case  throughout  vast 
areas  in  North  Wales  and  Cumberland.  I  read  the  lucid 
and  important  memoir  of  this  eminent  geologist  with  great 
interest :  it  placed  the  data  of  the  problem  before  me,  as 
far  as  they  were  then  known,  and  I  found  myself,  to  some 
extent  at  least,  in  a  condition  to  appreciate  the  value  of  a 
theoretic  explanation. 

Everybody  has  heard  of  the  force  of  gravitation,  and  of 
that  of  cohesion  ;  but  there  is  a  more  subtle  play  of  forces 
exerted  by  the  molecules  of  bodies  upon  each  other  when 
these  molecules  possess  sufficient  freedom  of  action.  In 
virtue  of  such  forces,  the  ultimate  particles  of  matter  are 
enabled  to  build  themselves  up  into  those  wondrous  edifices 
which  we  call  crystals.  A  diamond  is  a  crystal  self-erected 
from  atoms  of  carbon ;  an  amethyst  is  a  crystal  built  up 
from  particles  of  silica ;  Iceland  spar  is  a  crystal  built 


CRYSTALLIZATION   THEORY.  3 

by  particles  of  carbonate  of  lime.  By  artificial  means  we- 
can  allow  the  particles  of  bodies  the  free  play  necessary  to 
their  crystallization.  Thus  a  solution  of  saltpetre  exposed 
to  slow  evaporation  produces  crystals  of  saltpetre ;  alum 
crystals  of  great  size  and  beauty  may  be  obtained  in  a 
similar  manner ;  and  in  the  formation  of  a  bit  of  common 
sugar-candy  there  are  agencies  at  play,  the  contemplation 
of  which,  as  mere  objects  of  thought,  is  sufficient  to  make 
the  wisest  philosopher  bow  down  in  wonder,  and  confess 
himself  a  child. 

The  particles  of  certain  crystalline  bodies  are  found  to 
arrange  themselves  in  layers,  like  courses  of  atomic  ma- 
sonry, and  along  these  layers  such  crystals  may  be  easily 
cloven  into  the  thinnest  laminae.  Some  crystals  possess 
one  such  direction  in  which  they  may  be  cloven,  some 
several ;  some,  on  the  other  hand,  may  be  split  with  dif- 
ferent facility  in  different  directions.  Rock  salt  may  be 
cloven  with  equal  facility  in  three  directions  at  right  angles 
to  each  other  ;  that  is,  it  may  be  split  into  cubes ;  calcspar 
may  be  cloven  in  three  directions  oblique  to  each  other ; 
that  is,  into  rhomboids.  Heavy  spar  may  also  be  cloven 
in  three  directions,  but  one  cleavage  is  much  more  perfect, 
or  more  eminent  as  it  is  sometimes  called,  than  the  rest. 
Mica  is  a  crystal  which  cleaves  very  readily  in  one  direc- 
tion, and  it  is  sufficiently  tough  to  furnish  films  of  ex- 
treme tenuity :  finally,  any  boy,  with  sufficient  skill,  who 
tries  a  good  crystal  of  sugar-candy  in  various  directions 
with  the  blade  of  his  penknife,  will  find  that  it  possesses 
one  direction  in  particular,  along  which,  if  the  blade  of  the 
knife  be  placed  and  struck,  the  crystal  will  split  into  plates 
possessing  clean  and  shining  surfaces  of  cleavage. 

Professor  Sedgwick  was  intimately  acquainted  with  all 
these  facts,  and  a  great  many  more,  when  he  investigated 
the  cleavage  of  slate  rocks ;  and  seeing  no  other  explana- 
tion open  to  him,  he  ascribed  to  slaty  cleavage  a  crystal- 


4  POLAR  FORCES. 

line  origin.  He  supposed  that  the  particles  of  slate  rock 
were  acted  on,  after  their  deposition,  by  "  polar  forces," 
which  so  arranged  them  as  to  produce  the  cleavage.  Ac- 
cording to  this  theory,  therefore,  Honister  Crag  and  the 
cliffs  of  Penrhyn  are  to  be  regarded  as  portions  of  enor- 
mous crystals ;  a  length  of  time  commensurate  with  the 
vastness  of  the  supposed  action  being  assumed  to  have 
elapsed  between  the  deposition  of  the  rock  and  its  final 
crystallization. 

When,  however,  we  look  closely  into  this  bold  and  beau- 
tiful hypothesis,  we  find  that  the  only  analogy  which  exists 
between  the  physical  structure  of  slate  rocks  and  of  crys- 
tals is  this  single  one  of  cleavage.  Such  a  coincidence 
might  fairly  give  rise  to  the  conjecture  that  both  were  due 
to  a  common  cause  ;  but  there  is  great  difficulty  in  accept- 
ing this  as  a  theoretic  truth.  When  we  examine  the 
structure  of  a  slate  rock,  we  find  that  the  substance  is  com- 
posed of  the  debris  of  former  rocks ;  that  it  was  once  a  fine 
mud,  composed  of  particles  of  sensible  magnitude.  Is  it 
meant  that  these  particles,  each  taken  as  a  whole,  were  re- 
arranged after  deposition  ?  If  so,  the  force  which  effected 
such  an  arrangement  must  be  wholly  different  from  that 
of  crystallization,  for  the  latter  is  essentially  molecular. 
What  is  this  force  ?  Nature,  as  far  as  we  know,  furnishes 
none  competent,  under  the  conditions,  to  produce  the  effect, 
Is  it  meant  that  the  molecules  composing  these  sensible 
particles  have  re-arranged  themselves  ?  We  find  no  evi- 
dence of  such  an  action  in  the  individual  fragments ;  the 
mica  is  still  mica,  and  possesses  all  the  properties  of  mica ; 
and  so  of  the  other  ingredients  of  which  the  rock  is  com- 
posed. Independent  of  this,  that  an  aggregate  of  hetero- 
geneous mineral  fragments  should,  without  any  assignable 
external  cause,  so  shift  its  molecules  as  to  produce  a  plane 
of  cleavage  common  to  them  all,  is,  in  my  opinion,  an  as- 
sumption too  heavy  for  any  theory  to  bear. 


MECHANICAL  THEORY.  5 

Nevertheless,  the  paper  of  Professor  Sedgwick  invested 
the  subject  of  slaty  cleavage  with  an  interest  not  to  be 
forgotten,  and  proved  the  stimulus  to  further  inquiry. 
The  structure  of  slate-rocks  was  more  closely  examined  ; 
the  fossils  which  they  contained  were  subjected  to  rigid 
scrutiny,  and  their  shapes  compared  with  those  of  the  same 
species  taken  from  other  rocks.  Thus  proceeding,  the  late 
Mr.  Daniel  Sharpe  found  that  the  fossils  contained  in  slate- 
rocks  are  distorted  in  shape,  being  uniformly  flattened  out 
in  the  direction  of  the  planes  of  cleavage.  Here,  then,  was 
a  fact  of  capital  importance,  —  the  shells  became  the  indi- 
cators of  an  action  to  which  the  mass  containing  them  had 
been  subjected  ;  they  demonstrated  the  operation  of  pres- 
sure acting  at  right  angles  to  the  planes  of  cleavage. 
The  more  the  subject  was  investigated,  the  more  clearly 

I  were  the  evidences  of  pressure  made  out.  Subsequent  to 
Mr.  Sharpe,  Mr.  Sorby  entered  upon  this  field  of  inquiry. 
With  great  skill  and  patience  he  prepared  sections  of  slate 
rock,  which  he  submitted  to  microscopic  examination,  and 
his  observations  showed  that  the  evidences  of  pressure  could 
be  plainly  traced,  even  in  his  minute  specimens.  The  sub- 
ject has  been  since  ably  followed  up  by  Professors  Haugh  ton, 
Harkness,  and  others  ;  but  to  the  two  gentlemen  first  men- 
tioned we  are,  I  think,  indebted  for  the  prime  facts  on 

;  which  rests  the  mechanical  theory  of  slaty  cleavage.* 

The  observations  just  referred  to  showed  the  co-existence 
of  the  two  phenomena,  but  they  did  not  prove  that  pressure 
and  cleavage  stood  to  each  other  in  the  relation  of  cause 
and  effect.  "  Can  the  pressure  produce  the  cleavage  ?  " 

|  was  still  an  open  question,  and  it  was  one  which  mere  rea- 
soning, unaided  by  experiment,  was  incompetent  to  answer. 

*  Mr.  Sorby  has  drawn  my  attention  to  an  able  and  interesting  paper 
by  M.  Bauer,  in  Karsten's  '  Archiv '  for  1846  ;  in  which  it  is  announced  that 
cleavage  is  a  tension  of  the  mass  produced  by  pressure.  The  author  refers  to 
the  experiments  of  Mr.  Hopkins  as  bearing  upon  the  question. 


6       LECTURE  AT  THE  ROYAL  INSTITUTION. 

Sharpe  despaired  of  an  experimental  solution,  regarding 
our  means  as  inadequate,  and  our  time  on  earth  too  short 
to  produce  the  result.  Mr.  Sorby  was  more  hopeful.  Sub- 
mitting mixtures  of  gypsum  and  oxide  of  iron  scales  to 
pressure,  he  found  that  the  scales  set  themselves  approx- 
imately at  right  angles  to  the  direction  in  which  the  pres- 
sure was  applied.  The  position  of  the  scales  resembled 
that  of  the  plates  of  mica  which  his  researches  had  dis- 
closed to  him  in  slate-rock,  and  he  inferred  that  the  pre- 
sence of  such  plates,  and  of  flat  or  elongated  fragments 
generally,  lying  all  in  the  same  general  direction,  was  the 
cause  of  slaty  cleavage.  At  the  meeting  of  the  British 
Association  at  Glasgow,  in  1855, 1  had  the  pleasure  of 
seeing  some  of  Mr.  Sorby's  specimens,  and,  though  the 
cleavage  they  exhibited  was  very  rough,  still,  the  tendency 
to  yield  at  right  angles  to  the  direction  in  which  the  pres- 
sure had  been  applied,  appeared  sufficiently  manifest. 

At  the  time  now  referred  to,  I  was  engaged,  and  had 
been  for  a  long  time  previously,  in  examining  the  effects 
of  pressure  upon  the  magnetic  force,  and,  as  far  back  as 
1851,  I  had  noticed  that  some  of  the  bodies  which  I  had 
subjected  to  pressure  exhibited  a  cleavage  of  surpassing- 
beauty  and  delicacy.  The  bearing  of  such  facts  upon 
the  present  question  now  forcibly  occurred  to  me.  I  fol- 
lowed up  the  observations  ;  visited  slate-yards  and  quarries, 
observed  the  exfoliation  of  rails,  the  fibres  of  iron,  the  struc- 
ture of  tiles,  pottery,  and  cheese,  and  had  several  practical 
lessons  in  the  manufacture  of  puff-paste  and  other  lami- 
nated confectionery.  My  observations,  I  thought,  pointed 
to  a  theory  of  slaty  cleavage  different  from  any  previously 
given,  and  which,  moreover,  referred  a  great  number  of 
apparently  unrelated  phenomena  to  a  common  cause.  On 
the  10th  of  June,  1856, 1  made  them  the  subject  of  a 
Friday  evening's  discourse  at  the  Royal  Institution. 

Such  are  the  circumstances,  apparently  remote  enough. 


ORIGIN   OF  RESEARCHES.  7 

under  which  my  connexion  with  glaciers  originated.  My 
friend,  Professor  Huxley,  was  present  at  the  lecture  re- 
ferred to  :  lie  was  well  acquainted  with  the  work  of  Pro- 
fessor Forbes,  entitled  "  Travels  in  the  Alps,"  and  he 
surmised  that  the  question  of  slaty  cleavage,  in  its  new 
aspect,  might  have  some  bearing  upon  the  laminated  struc- 
ture of  glacier-ice  discussed  in  the  work  referred  to.  He 
therefore  urged  me  to  read  the  "  Travels,"  which  I  did 
with  care,  and  the  book  made  the  same  impression  upon 
me  that  it  had  produced  upon  my  friend.  We  were  both 
going  to  Switzerland  that  year,  and  it  required  but  a  slight 
modification  of  our  plans  to  arrange  a  joint  excursion  over 
some  of  the  glaciers  of  the  Oberland,  and  thus  afford  our- 
selves the  means  of  observing  together  the  veined  struc- 
ture of  the  ice. 

Had  the  results  of  this  arrangement  been  revealed  to  me 
beforehand,  I  should  have  paused  before  entering  upon  an 
investigation  which  required  of  me  so  long  a  renunciation 
of  my  old  and  more  favourite  pursuits.  But  no  man  knows 
when  he  commences  the  examination  of  a  physical  problem 
into  what  new  and  complicated  mental  alliances  it  may 
lead  him.  No  fragment  of  nature  can  be  studied  alone  : 
each  part  is  related  to  every  other  part ;  and  hence  it  is, 
that,  following  up  the  links  of  law  which  connect  pheno- 
mena, the  physical  investigator  often  finds  himself  led  far 
beyond  the  scope  of  his  original  intentions,  the  danger  in 
this  respect  augmenting  in  direct  proportion  to  the  wish  of 
the  inquirer  to  render  his  knowledge  solid  and  complete. 

When  the  idea  of  writing  this  book  first  occurred  to  me, 
it  was  not  my  intention  to  confine  myself  to  the  glaciers 
alone,  but  to  make  the  work  a  vehicle  for  the  familiar  ex- 
planation of  such  general  physical  phenomena  as  had  come 
under  my  notice.  Nor  did  I  intend  to  address  it  to  a  cul- 
tured man  of  science,  but  to  &  youth  of  average  intelligence, 
and  furnished  with  the  education  which  England  now  offers 


8  A  BOY'S  BOOK. 

to  the  young.  I  wished  indeed  to  make  it  a  boy's  class- 
book,  which  should  reveal  the  mode  of  life,  as  well  as  the 
scientific  objects,  of  an  explorer  of  the  Alps.  The  incidents 
of  the  past  year  have  caused  me  to  deviate,  in  some  degree, 
from  this  intention,  but  its  traces  will  be  sufficiently  mani- 
fest; and  this  reference  to  it  will,  I  trust,  excuse  an 
occasional  liberty  of  style  and  simplicity  of  treatment 
which  would  be  out  of  place  if  intended  for  a  reader  of 
riper  years. 


1856.]  THE  OBERLAND. 


EXPEDITION   OF   1856. 

t 

THE   OBERLAND. 

(2.) 

ON  the  16th  of  August,  1856, 1  received  my  Alpenstock 
from  the  hands  of  Dr.  Hooker,  in  the  garden  of  the  Pension 
Ober,  at  Interlaken.  It  bore  my  name,  not  marked,  how- 
ever, by  the  vulgar  brands  of  the  country,  but  by  the  solar 
beams  which  had  been  converged  upon  it  by  the  pocket 
lens  of  my  friend.  I  was  the  companion  of  Mr.  Huxley, 
and  our  first  aim  was  to  cross  the  Wengern  Alp.  Light 
and  shadow  enriched  the  crags  and  green  slopes  as  we 
advanced  up  the  valley  of  Lauterbrunnen,  and  each 
occupied  himself  with  that  which  most  interested  him. 
My  companion  examined  the  drift,  I  the  cleavage,  while 
both  of  us  looked  with  interest  at  the  contortions  of  the 
strata  to  our  left,  and  at  the  shadowy,  unsubstantial  aspect 
of  the  pines,  gleaming  through  the  sun-haze  to  our  right. 

What  was  the  physical  condition  of  the  rock  when  it  was 
thus  bent  and  folded  like  a  pliant  mass  ?  Was  it  neces- 
sarily softer  than  it  is  at  present  ?  I  do  not  think  so.  The 
shock  which  would  crush  a  railway  carriage,  if  communi- 
cated to  it  at  once,  is  harmless  when  distributed  over  the 
interval  necessary  for  the  pushing  in  of  the  buffer.  By 
suddenly  stopping  a  cock  from  which  water  flows  you  may 
burst  the  conveyance  pipe,  while  a  slow  turning  of  the  cock 
keeps  all  safe.  Might  not  a  solid  rock  by  ages  of  pressure 
be  folded  as  above  ?  It  is  a  physical  axiom  that  no  body  is 
perfectly  hard,  none  perfectly  soft,  none  perfectly  elastic. 
The  hardest  body  subjected  to  pressure  yields,  however 
little,  and  the  same  body  when  the  pressure  is  removed 


10  FOLDED  ROCKS.  [1856. 

cannot  return  to  its  original  form.  If  it  did  not  yield  in 
the  slightest  degree  it  would  be  perfectly  hard  ;  if  it  could 
completely  return  to  its  original  shape  it  would  be  per- 
fectly elastic. 

Let  a  pound  weight  be  placed  upon  a  cube  of  granite  : 
the  cube  is  flattened,  though  in  an  infinitesimal  degree. 
Let  the  weight  be  removed,  the  cube  remains  a  little 
flattened  ;  it  cannot  quite  return  to  its  primitive  condition. 
Let  us  call  the  cube  thus  flattened  No.  1.  Starting  with 
No.  1  as  a  new  mass,  let  the  pound  weight  be  laid  upon  it : 
the  mass  yields,  and  on  removing  the  weight  it  cannot 
return  to  the  dimensions  of  No.  1 ;  we  have  a  more  flat- 
tened mass,  No.  2.  Proceeding  in  this  manner,  it  is 
manifest  that  by  a  repetition  of  the  process  we  should  pro- 
duce a  series  of  masses,  each  succeeding  one  more  flat- 
tened than  the  former.  This  appears  to  be  a  necessary 
consequence  of  the  physical  axiom  referred  to  above. 

Now  if,  instead  of  removing  and  replacing  the  weight  in 
the  manner  supposed,  we  cause  it  to  rest  continuously 
upon  the  cube,  the  flattening,  which  above  was  intermit- 
tent, will  be  continuous ;  no  matter  how  hard  the  cube 
may  be,  there  will  be  a  gradual  yielding  of  its  mass  under 
the  pressure.  Apply  this  to  squeezed  rocks,  —  to  those, 
for  example,  which  form  the  base  of  an  obelisk  like  the 
Matte rhorn ;  that  this  base  must  yield,  seems  a  certain 
consequence  of  the  physical  constitution  of  matter ;  the 
conclusion  seems  inevitable,  that  the  mountain  is  sinking 
by  its  own  weight.  Let  two  points  be  fixed,  one  near  the 
summit,  the  other  near  the  base  of  the  obelisk ;  next  year 
these  points  will  have  approached  each  other.  Whether 
the  amount  of  approach  in  a  human  lifetime  be  measure- 
able  we  know  not ;  but  it  seems  certain  that  ages  would 
leave  their  impress  upon  the  mass,  and  render  visible  «to 
the  eye  an  action  which  at  present  is  appreciable  by  the 
imagination  only. 


1856.]  THE  JUNGFRAU  AND   SILBERHORN.  11 

We  halted  on  the  night  of  the  16th  at  the  Jungfrau 
Hotel,  and  next  morning  we  saw  the  beams  of  the  rising 
sun  fall  upon  the  peaked  snow  of  the  Silberhorn.  Slowly 
and  solemnly  the  pure  white  cone  appeared  to  rise  higher 
and  higher  into  the  sunlight,  being  afterwards  mottled 
with  gold  and  gloom,  as  clouds  drifted  between  it  and  the 
sun.  I  descended  alone  towards  the  base  of  the  mountain, 
making  my  way  through  a  rugged  gorge,  the  sides  of 
which  were  strewn  with  pine-trees,  splintered,  broken 
across,  and  torn  up  by  the  roots.  I  finally  reached  the 
end  of  a  glacier,  formed  by  the  snow  and  shattered  ice 
which  fall  from  the  shoulders  of  the  Jungfrau.  The  view 
from  this  place  had  a  savage  magnificence  such  as  I  had 
not  previously  beheld,  and  it  was  not  without  some  slight 
feeling  of  awe  that  I  clambered  up  the  end  of  the  glacier. 
It  was  the  first  I  had  actually  stood  upon.  The  lone- 
liness of  the  place  was  very  impressive,  the  silence  being 
only  broken  by  fitful  gusts  of  wind,  or  by  the  weird  rattle 
of  the  de'bris  which  fell  at  intervals  from  the  melting  ice. 

Once  I  noticed  what  appeared  to  be  the  sudden  and 
enormous  augmentation  of  the  waters  of  a  cascade,  but  the 
sound  soon  informed  me  that  the  increase  was  due  to  an 
avalanche  which  had  chosen  the  track  of  the  cascade  for 
its  rush.  Soon  afterwards  my  eyes  were  fixed  upon  a  white 
slope  some  thousands  of  feet  above  me  :  I  saw  the  ice 
give  way,  and,  after  a  sensible  interval,  the  thunder  of 
another  avalanche  reached  me.  A  kind  of  zigzag  chan- 
nel had  been  worn  on  the  side  of  the  mountain,  and 
through  this  the  avalanche  rushed,  hidden  at  intervals,  and 
anon  shooting  forth,  and  leaping  like  a  cataract  down  the 
precipices.  The  sound  was  sometimes  continuous, .  but 
sometimes  broken  into  rounded  explosions  which  seemed 
to  assert  a  passionate  predominance  over  the  general  level 
of  the  roar.  These  avalanches,  when  they  first  give  way, 
usually  consist  of  enormous  blocks  of  ice,  which  are  more 


12  AVALANCHES.  [1856. 

and  more  shattered  as  they  descend.  Partly  to  the  echos 
of  the  first  crash,  but  mainly,  I  think,  to  the  shock  of  the 
harder  masses  which  preserve  their  cohesion,  the  explo- 
sions which  occur  during  the  descent  of  the  avalanche  are 
to  be  ascribed.  Much  of  the  ice  is  crushed  to  powder ;  and 
thus,  when  an  avalanche  pours  cataract-like  over  a  ledge, 
the  heavier  masses,  being  less  influenced  by  the  atmos- 
pheric resistance,  shoot  forward  like  descending  rockets, 
leaving  the  lighter  powder  in  trains  behind  them.  Such  is 
the  material  of  which  a  class  of  the  smaller  glaciers  in  the 
Alps  is  composed.  They  are  the  products  of  avalanches, 
the  crushed  ice  being  recompacted  into  a  solid  mass, 
which  exhibits  on  a  smaller  scale  most  of  the  character- 
istics of  the  large  glaciers. 

After  three  hours'  absence  I  reascended  to  the  hotel, 
breakfasted,  and  afterwards  returned  with  Mr.  Huxley  to 
the  glacier.  While  we  were  engaged  upon  it  the  weather 
suddenly  changed ;  lightning  flashed  about  the  summits 
of  the  Jungfrau,  and  thunder  "  leaped  "  among  her  crags. 
Heavy  rain  fell,  but  it  cleared  up  afterwards  with  magical 
speed,  and  we  returned  to  our  hotel.  Heedless  of  the 
forebodings  of  many  prophets  of  evil  weather,  we  set  out 
for  Grindelwald.  The  scene  from  the  summit  of  the  little 
Scheideck  was  exceedingly  grand.  The  upper  air  ex- 
hibited a  commotion  which  we  did  not  experience  ;  clouds 
were  wildly  driven  against  the  flanks  of  the  Eiger,  the 
Jungfrau  thundered  behind,  while  in  front  of  us  a  magni- 
ficent rainbow,  fixing  one  of  its  arms  in  the  valley  of 
Grindelwald,  and  throwing  the  other  right  over  the  crown 
of  the  Wetterhorn,  clasped  the  mountain  in  its  embrace. 
Through  jagged  apertures  in  the  clouds  floods  of  golden 
light  were  poured  down  the  sides  of  the  mountain.  On 
the  slopes  were  innumerable  chalets,  glistening  in  the 
sunbeams,  herds  browsing  peacefully  and  shaking  their 
mellow  bells ;  while  the  blackness  of  the  pine-trees,  crowded 


1856.]  THE  HEISSE  PLATTE.  13 

into  woods,  or  scattered  in  pleasant  clusters  over  alp  and 
valley,  contrasted  forcibly  with  the  lively  green  of  the 
fields. 

At  Grindelwald,  on  the  18th,  we  engaged  a  strong  and 
competent  guide,  named  Christian  Kaufmann,  and  pro- 
ceeded to  the  Lower  Glacier.  After  a  steep  ascent,  we 
gained  a  point  from  which  we  could  look  down  upon  the 
frozen  mass.  At  first  the  ice  presented  an  appearance  of 
utter  confusion,  but  we  soon  reached  a  position  where  the 
mechanical  conditions  of  the  glacier  revealed  themselves, 
and  where  we  might  learn,  had  we  not  known  it  before, 
that  confusion  is  merely  the  unknown  intermixture  of  laws, 
and  becomes  order  and  beauty  when  we  rise  to  their  com- 
prehension. We  reached  the  so-called  Eismeer, — Ice  Sea. 
In  front  of  us  was  the  range  of  the  Viescherhorner,  and  a 
vast  snow  slope,  from  which  one  branch  of  the  glacier 
was  fed.  Near  the  base  of  this  neve,  and  surrounded  on 
all  sides  by  ice,  lay  a  brown  rock,  to  which  our  attention 
was  directed  as  a  place  noted  for  avalanches  ;  on  this 
rock  snow  or  ice  never  rests,  and  it  is  hence  called  the 
Heisse  Platte,  —  the  Hot  Plate.  At  the  base  of  the  rock, 
and  far  below  it,  the  glacier  was  covered  with  clean  crushed 
ice,  which  had  fallen  from  a  crown  of  frozen  cliffs  en- 
circling the  brow  of  the  rock.  One  obelisk  in  particular 
signalised  itself  from  all  others  by  its  exceeding  grace  and 
beauty.  Its  general  surface  was  dazzling  white,  but  from 
its  clefts  and  fissures  issued  a  delicate  blue  light,  which 
deepened  in  hue  from  the  edges  inwards.  It  stood  upon  a 
pedestal  of  its  own  substance,  and  seemed  as  accurately 
fixed  as  if  rule  and  plummet  had  been  employed  in  its 
erection.  Fig.  1  represents  this  beautiful  minaret  of  ice. 
While  we  were  in  sight  of  the  Heisse  Platte,  a  dozen 
avalanches  rushed  downwards  from  its  summit.  In  most 
cases  we  were  informed  of  the  descent  of  an  avalanche  by 
the  sound,  but  sometimes  the  white  mass  was  seen  gliding 


14 


ICE   MINARET. 


[1856. 


down  the  rock,  and  scattering  its  smoke  in  the  air,  long 
before  the  sound  reached  us.  It  is  difficult  to  reconcile  the 
insignificant  appearance  presented  by  avalanches,  when 
seen  from  a  distance,  with  the  volume  of  sound  which  they 


Fig.  1. 

generate  ;  but  on  this  day  we  saw  sufficient  to  account  for 
the  noise.  One  block  of  solid  ice  which  we  found  below 
the  Heisse  Platte  measured  7  feet  6  inches  in  length,  5 
feet  8  inches  in  height,  and  4  feet  6  inches  in  depth.  A 
second  mass  was  10  feet  long,  8  feet  high,  and  6  feet  wide. 
It  contained  therefore  480  cubic  feet  of  ice,  which  had 
been  cast  to  a  distance  of  nearly  1,000  yards  down  the 
glacier.  The  shock  of  such  hard  and  ponderous  projec- 
tiles against  rocks  and  ice,  reinforced  by  the  echos  from 


1856.]  ECHOS   OF   THE  WETTERHORN.  15 

the  surrounding  mountains,  will  appear  sufficient  to  ac- 
count for  the  peals  by  which  their  descent  is  accompanied. 
A  second  day,  in  company  with  Dr.  Hooker,  completed 
the  examination  of  this  glacier  in  1856  ;  after  which  I 
parted  from  my  friends,  Mr.  Huxley  intending  to  rejoin  me 
at  the  Grimsel.     On  the  morning  of  the  20th  of  August  I 
strapped  on  my  knapsack  and  ascended  the  green  slopes 
from  Grindelwald  towards  the  great  Scheideck.     Before 
j  reaching  the  summit  I  frequently  heard  the  wonderful 
!  echos  of  the  Wetterhorn.     Some  travellers  were  in  ad- 
j  vance  of  me,  and  to  amuse  them  an  alpine  horn  was 
blown.     The  direct  sound  was  cut  off  from  me  by  a  hill, 
'  but  the  echos  talked  down   to  me  from  the  mountain 
j  walls.     The  sonorous  waves  arrived  after  one,  two,  three, 
and  more  reflections,  diminishing  gradually  in  intensity, 
but  increasing  in  softness,  as  if  in  its  wanderings  from 
1  crag  to  crag  the  sound  had  undergone  a  kind  of  sifting 
process,  leaving  all  its  grossness  behind,  and  returning  in 
delightful  flute-notes  to  the  ear. 

Let  us  investigate  this  point  a  little.  If  two  looking- 
glasses  be  placed  perfectly  parallel  to  each  other,  with  a 
•  lighted  candle  between  them,  an  infinite  series  of  images 
of  the  candle  will  be  seen  at  both  sides,  the  images  dimin- 
ishing in  brightness  the  further  they  recede.  But  if  the 
looking-glasses,  instead  of  being  parallel,  enclose  an  angle, 
a  limited  number  of  images  only  will  be  seen.  The 
mailer  the  angle  which  the  reflectors  make  with  each 
)ther,  or,  in  other  words,  the  nearer  they  approach  parallel- 
sm,  the  greater  will  be  the  number  of  images  observed. 

To  find  the  number  of  images  the  following  is  the  rule. 
)ivide  360,  or  the  number  of  degrees  in  a  circle,  by  the 
lumber  of  degrees  in  the  angle  enclosed  by  the  two  mir- 
rors, the  quotient  will  be  one  more  than  the  number  of 
mages  ;  or,  counting  the  object  itself,  the  quotient  is  al- 
vays  equal  to  the  number  of  images  plus  the  object.  In 


16 


ECHOS  EXPLAINED. 


[1856. 


Fig.  2, 1  have  given  the  number  and  position  of  the  images ; 
produced  by  two  mirrors  placed  at  an  angle  of  45°.     A  B 

and  B  C  mark  the  edges  j 
of  the  mirrors,  and  0  rep- 
resents the  candle,  which,  i 
for  the  sake  of  simplicity,  | 
I  have  placed  midway  j 
between  them.  Fix  onej 
8  point  of  a  pair  of  com-; 
passes  at  B,  and  with, 
the  distance  B  0  sweep  a| 
circle  :  —  all  the  imagesl 
will  be  ranged  upon  the\ 
circumference  of  this  cir-\ 
cle.  The  number  of  im-l 
ages  found  by  the  fore-j 
going  rule  is  7,  and  their  positions  are  marked  in  thej 
figure  by  the  numbers  1,  2,  3,  &c. 

Suppose  the  ear  to  occupy  the  place  of  the  eye,  and- 
that  a  sounding  body  occupies  the  place  of  the  lurmnousi 
one,  we  should  then  have  just  as  many  echos  as  we  had 
images  in  the  former  case.  These  echos  would  diminish} 
in  loudness  just  as  the  images  of  the  candle  diminish  ini 
brightness.  At  each  reflection  a  portion  both  of  sound! 
and  light  is  lost ;  hence  the  oftener  light  is  reflected  the- 
dimmer  it  becomes,  and  the  oftener  sound  is  reflected  the> 
fainter  it  is. 

Now  the  cliffs  of  the  Wetterhorn  are  so  many  rough 
angular  reflectors  of  the  sound :  some  of  them  send  it  back 
directly  to  the  listener,  and  we  have  a  first  echo ;  some  ol 
them  send  it  on  to  others,  from  which  it  is  again  re-! 
fleeted,  forming  a  second  echo.  Thus,  by  repeated  reflec- 
tion, successive  echos  are  sent  to  the  ear,  until,  at  length, 
they  become  so  faint  as  to  be  inaudible.  The  sound,  as 
it  diminishes  in  intensity,  appears  to  come  from  greater 


1856.]  KEICHENBACH  AND  HANDECK.  17 

and  greater  distances,  as  if  it  were  receding  into  the  moun- 
tain solitudes  ;  the  final  echos  being  inexpressibly  soft  and 
pure. 

After  crossing  the  Scheideck  I  descended  to  Meyringen, 
visiting  the  Reichenbach  waterfall  on  my  way.  A  pecu- 
liarity of  the  descending  water  here  is,  that  it  is  broken  up 
in  one  of  the  basins  into  nodular  masses,  each  of  which  in 
falling  leaves  the  light  foaming  mass  which  surrounds  it 
as  a  train  in  the  air  behind  ;  the  effect  exactly  resembles 
that  of  the  avalanches  of  the  Jungfrau,  in  which  the  more 
solid  blocks  of  ice  shoot  forward  in  advance  of  the  lighter 
de'bris,  which  is  held  back  by  the  friction  of  the  air. 

Next  day  I  ascended  the  valley  of  Hasli,  and  observed 
upon  the  rocks  and  mountains  the  action  of  ancient  glaciers 
which  once  filled  the  valley  to  the  height  of  more  than  a 
thousand  feet  above  its  present  level.  I  paused,  of  course, 
at  the  waterfall  of  Handeck,  and  stood  for  a  time  upon 
the  wooden  bridge  which  spans  the  river  at  its  top.  The 
Aar  comes  gambolling  down  to  the  bridge  from  its  parent 
glacier,  takes  one  short  jump  upon  a  projecting  ledge, 
boils  up  into  foam,  and  then  leaps  into  a  chasm,  from  the 
bottom  of  which  its  roar  ascends  through  the  gloom.  A 
rivulet  named  the  Aarlenbach  joins  the  Aar  from  the  left 
in  the  very  jaws  of  the  chasm :  falling,  at  first,  upon  a 
projection  at  some  depth  below  the  edge,  and  rebound- 
ing from  this,  it  darts  at  the  Aar,  and  both  plunge  to- 
gether like  a  pair  of  fighting  demons  to  the  bottom  of 
the  gorge.  The  foam  of  the  Aarlenbach  is  white,  that 
of  the  Aar  is  yellow,  and  this  enables  the  observer  to  trace 
the  passage  of  the  one  cataract  through  the  other.  As  I 
stood  upon  the  bridge  the  sun  shone  brightly  upon  the 
spray  and  foam  ;  my  shadow  was  oblique  to  the  river,  and 
hence  a  symmetrical  rainbow  could  not  be  formed  in  the 
•spray,  but  one  half  of  a  lovely  bow,  with  its  base  in  the 
chasm,  leaned  over  against  the  opposite  rocks,  the  colours 
2 


18  HUT   OF  M.  DOLFUSS.  [1856. 

advancing  and  retreating  as  the  spray  shifted  its  position. 
I  had  been  watching  the  water  intently  for  some  time, 
when  a  little  Swiss  boy,  who  stood  beside  me,  observed, 
in  his  trenchant  German,  "  There  plunge  stones  ever 
downwards."  The  stones  were  palpable  enough,  carried 
down  by  the  cataract,  and  sometimes  completely  breaking 
loose  from  it,  but  I  did  not  see  them  until  my  attention 
was  withdrawn  from  the  water. 

On  my  arrival  at  the  Grimsel  I  found  Mr.  Huxley  already 
there,  and,  after  a  few  minutes'  conversation,  we  decided  to 
spend  a  night  in  a  hut  built  by  M.  Dolfuss  in  1846,  beside 
the  Unteraar  glacier,  about  2,000  feet  above  the  Hospice. 
We  hoped  thus  to  be  able  to  examine  the  glacier  to  its 
origin  on  the  following  day.  Two  days'  food  and  some 
blankets  were  sent  up  from  the  Hospice,  and,  accompanied 
by  our  guide,  we  proceeded  to  the  glacier. 

Having  climbed  a  great  terminal  moraine,  and  tramped 
for  a  considerable  time  amid  loose  shingle  and  boulders, 
we  came  upon  the  ice.  The  finest  specimens  of"  tables  '• 
which  I  have  ever  seen  are  to  be  found  upon  this  glacier, 
—  huge  masses  of  clean  granite  poised  on  pedestals  of  ice. 
Here  are  also  "  dirt-cones  "  of  the  largest  size,  and  nume- 
rous shafts,  the  forsaken  passages  of  ancient  "  moulins," 
some  filled  with  water,  others  simply  with  deep  blue  light. 
I  reserve  the  description  and  explanation  of  both  cones 
and  moulins  for  another  place.  The  surfaces  of  some  of 
the  small  pools  were  sprinkled  lightly  over  with  snow, 
which  the  water  underneath  was  unable  to  melt ;  a  coating 
of  snow  granules  was  thus  formed,  flexible  as  chain  armour, 
but  so  close  that  the  air  could  not  escape  through  it. 
Some  bubbles  which  had  risen  through  the  water  had  lifted 
the  coating  here  and  there  into  little  rounded  domes, 
which,  by  gentle  pressure,  could  be  shifted  hither  and  thither, 
and  several  of  them  collected  into  one.  We  reached  the 
hut,  the  floor  of  which  appeared  to  be  of  the  original  moun- 


1856.]  HOTEL  DES  NEUFCHATELOIS.  19 

tain  slab  ;  there  was  a  space  for  cooking  walled  off  from 
the  sleeping-room,  half  of  which  was  raised  above  the  floor, 
and  contained  a  quantity  of  old  hay.  The  number  2,404 
metres,  the  height,  I  suppose,  of  the  place  above  the  sea, 
was  painted  on  the  door,  behind  which  were  also  the  names 
of  several  well-known  observers  —  Agassiz,  Forbes,  Desor, 
Dolfuss,  Ramsay,  and  others  —  cut  in  the  wood.  Aloft 
contained  a  number  of  instruments  for  boring,  a  surveyor's 
chain,  ropes,  and  other  matters.  After  dinner  I  made  my 
way  alone  towards  the  junction  of  the  Finsteraar  and 
Lauteraar  glaciers,  which  unite  at  the  Abschwung  to  form 
the  trunk  stream  of  the  Unteraar  glacier.  Upon  the  great 
central  moraine  which  runs  between  the  branches  were 
perched  enormous  masses  of  rock,  and,  under  the  over- 
hanging ledge  of  one  of  these,  M.  Agassiz  had  his  Hotel 
des  Neufchdtelois.  The  rock  is  still  there,  bearing  traces 
of  names  now  nearly  obliterated  by  the  weather,  while  the 
fragments  around  also  bear  inscriptions.  There  in  the 
wilderness,  in  the  gray  light  of  evening,  these  blurred  and 
faded  evidences  of  human  activity  wore  an  aspect  of  sad- 
ness. It  was  a  temple  of  science  now  in  ruins,  and  I  a 
solitary  pilgrim  to  the  desecrated  blocks.  As  the  day  de- 
clined, rain  began  to  fall,  and  I  turned  my  face  towards 
my  new  home  ;  where  in  due  time  we  betook  ourselves  to 
our  hay,  and  waited  hopefully  for  the  morning. 

But  our  hopes  were  doomed  to  disappointment.  A  vast 
quantity  of  snow  fell  during  the  night,  and,  when  we  arose, 
we  found  the  glacier  covered,  and  the  air  thick  with  the 
descending  flakes.  We  waited,  hoping  that  it  might  clear 
up,  but  noon  arrived  and  passed  without  improvement ; 
our  fire-wood  was  exhausted,  the  weather  intensely  cold, 
and,  according  to  the  men's  opinion,  hopelessly  bad ; 
they  opposed  the  idea  of  ascending  further,  and  we  had 
therefore  no  alternative  but  to  pack  up  and  move  down- 
wards. What  was  snow  at  the  higher  elevations  changed 


20  THE   RHONE   GLACIER.  [1856. 

to  rain  lower  down,  and  drenched  us  completely  before  we 
reached  the  Grimsel.  But  though  thus  partially  foiled  in 
our  design,  this  visit  taught  us  much  regarding  the  struc- 
ture and  general  phenomena  of  the  glacier. 

The  morning  of  the  24th  was  clear  and  calm :  we  rose 
with  the  sun,  refreshed  and  strong,  and  crossed  the  Grimsel 
pass  at  an  early  hour.  The  view  from  the  summit  of  the 
pass  was  lovely  in  the  extreme  ;  the  sky  a  deep  blue,  the 
surrounding  summits  all  enamelled  with  the  newly-fallen 
snow,  which  gleamed  with  dazzling  whiteness  in  the  sun- 
light. It  was  Sunday,  and  the  scene  was  itself  a  Sabbath, 
with  no  sound  to  disturb  its  perfect  rest.  In  a  lake  which 
we  passed  the  mountains  were  mirrored  without  distortion, 
for  there  was  no  motion  of  the  air  to  ruffle  its  surface. 
From  the  summit  of  the  Mayenwand  we  looked  down  upon 
the  Rhone  glacier,  and  a  noble  object  it  seemed, — I  hard- 
ly know  a  finer  of  its  kind  in  the  Alps.  Forcing  itself 
through  the  narrow  gorge  which  holds  the  ice  cascade  in 
its  jaws,  and  where  it  is  greatly  riven  and  dislocated,  it 
spreads  out  in  the  valley  below  in  such  a  manner  as 
clearly  to  reveal  to  the  mind's  eye  the  nature  of  the 
forces  to  which  it  is  subjected.  Longfellow's  figure  is  quite 
correct ;  the  glacier  resembles  a  vast  gauntlet,  of  which  the 
gorge  represents  the  wrist ;  while  the  lower  glacier,  cleft 
by  its  fissures  into  finger-like  ridges,  is  typified  by  the  hand. 

Furnishing  ourselves  with  provisions  at  the  adjacent  inn, 
we  devoted  some  hours  to  the  examination  of  the  lower 
portion  of  the  glacier.  The  dirt  upon  its  surface  was 
arranged  in  grooves  as  fine  as  if  produced  by  the  passage 
of  a  rake,  while  the  laminated  structure  of  the  deeper  ice 
always  corresponded  to  the  superficial  grooving.  We 
found  several  shafts,  some  empty,  some  filled  with  water. 
At  one  place  our  attention  was  attracted  by  a  singular 
noise,  evidently  produced  by  the  forcing  of  air  and  water 
through  passages  in  the  body  of  the  glacier ;  the  sound 


1856.]  KINGS  AROUND   THE   SUN.  21 

rose  and  fell  for  several  minutes,  like  a  kind  of  intermit- 
tent snore,  reminding  one  of  Hugi's  hypothesis  that  the 
glacier  was  alive. 

We  afterwards  climbed  to  a  point  from  which  the  whole 
glacier  was  visible  to  us  from  its  origin  to  its  end.  Adjacent 
to  us  rose  the  mighty  mass  of  the  Finsteraarhorn,  the 
monarch  of  the  Oberland.  The  Galenstock  was  also  at 
hand,  while  round  about  the  neve  of  the  glacier  a  moun- 
tain wall  projected  its  jagged  outline  against  the  sky.  At 
a  distance  was  the  grand  cone  of  the  Weisshorn,  then,  and  I 
believe  still,  unsealed  ;  further  to  the  left  the  magnificent 
peaks  of  the  Mischabel ;  while  between  them,  in  savage 
isolation,  stood  the  obelisk  of  the  Matterhorn.  Near  us  was 
the  chain  of  the  Furca,  all  covered  with  shining  snow,  while 
overhead  the  dark  blue  of  the  firmament  so  influenced 
the  general  scene  as  to  inspire  a  sentiment  of  wonder 
approaching  to  awe.  We  descended  to  the  glacier,  and 
proceeded  towards  its  source.  As  we  advanced,  an  unu- 
sual light  fell  upon  the  mountains,  and  looking  upwards 
we  saw  a  series  of  coloured  rings,  drawn  like  a  vivid 
circular  rainbow  quite  round  the  sun.  Between  the  orb 
and  us  spread  a  thin  veil  of  cloud,  on  which  the  circles 
were  painted ;  the  western  side  of  the  veil  soon  melted 
away,  and  with  it  the  colours,  but  the  eastern  half  remained 
a  quarter  of  an  hour  longer,  and  then  in  its  turn  disap- 
peared. The  crevasses  became  more  frequent  and  dan- 
gerous as  we  ascended.  They  were  usually  furnished  with 
overhanging  eaves  of  snow,  from  which  long  icicles  de- 
pended, and  to  tread  on  which  might  be  fatal.  We  were 
near  the  source  of  the  glacier,  but  the  time  necessary  to 
reach  it  was  nevertheless  indefinite,  so  great  was  the  en- 
tanglement of  fissures.  We  followed  one  huge  chasm  for 
some  hundreds  of  yards,  hoping  to  cross  it ;  but  after  half 
an  hour's  fruitless  effort  we  found  ourselves  baffled  and 
forced  to  retrace  our  steps. 


22  SPIRIT   OF   THE   BROCKEN.  [1856. 

The  sun  was  sloping  to  the  west,  and  we  thought  it  wise 
to  return  ;  so  down  the  glacier  we  went,  mingling  our 
footsteps  with  the  tracks  of  chamois,  while  the  frightened 
marmots  piped  incessantly  from  the  rocks.  We  reached 
the  land  once  more,  and  halted  for  a  time  to  look  upon 
the  scene  within  view.  The  marvellous  blueness  of  the 
sky  in  the  earlier  part  of  the  day  indicated  that  the  air  was 
charged,  almost  to  saturation,  with  transparent  aqueous 
vapour.  As  the  sun  sank  the  shadow  of  the  Finsteraar- 
horn  was  cast  through  the  adjacent  atmosphere,  which, 
thus  deprived  of  the  direct  rays,  curdled  up  into  visible 
fog.  The  condensed  vapour  moved  slowly  along  the  flanks 
of  the  mountain,  and  poured  itself  cataract-like  into  the 
valley  of  the  Rhone.  Here  it  met  the  sun  again,  which 
reduced  it  once  more  to  the  invisible  state.  Thus,  though 
there  was  an  incessant  supply  from  the  generator  behind, 
the  fog  made  no  progress ;  as  in  the  case  of  the  moving 
glacier,  the  end  of  the  cloud-river  remained  stationary 
where  consumption  was  equal  to  supply.  Proceeding  along 
the  mountain  to  the  Furca,  we  found  the  valley  at  the 
further  side  of  the  pass  also  filled  with  fog,  which  rose,  like 
a  wall,  high  above  the  region  of  actual  shadow.  Once  on 
turning  a  corner  an  exclamation  of  surprise  burst  simul- 
taneously from  my  companion  and  myself.  Before  each 
of  us,  and  against  the  wall  of  fog,  stood  a  spectral  image 
of  a  man,  of  colossal  dimensions ;  dark  as  a  whole,  but 
bounded  by  a  coloured  outline.  We  stretched  forth  our 
arms ;  the  spectres  did  the  same.  We  raised  our  alpen- 
stocks ;  the  spectres  also  flourished  their  batons.  All  our 
actions  were  imitated  by  these  fringed  and  gigantic  shades. 
We  had,  in  fact,  the  Spirit  of  the  Brocken  before  us  in 
perfection. 

At  the  time  here  referred  to  I  had  had  but  little  expe- 
rience of  alpine  phenomena.  I  had  been  through  the 
Oberland  in  1850,  but  was  then  too  ignorant  to  learn 


1856.]  THE   TYROL.  23 

much  from  my  excursion.  Hence  the  novelty  of  this  day's 
experience  may  have  rendered  it  impressive :  still  even 
now  I  think  there  was  an  intrinsic  grandeur  in  its  pheno- 
mena which  entitles  the  day  to  rank  with  the  most  re- 
markable that  I  have  spent  among  the  Alps.  At  the 
Furca,  to  my  great  regret,  the  joint  ramblings  of  my 
friend  and  myself  ended ;  I  parted  from  him  on  the 
mountain  side,  and  watched  him  descending,  till  the  gray 
of  evening  finally  hid  him  from  my  view. 


THE   TYROL. 

(3.) 

MY  subsequent  destination  was  Vienna ;  but  I  wished 
to  associate  with  my  journey  thither  a  visit  to  some  of  the 
glaciers  of  the  Tyrol.  At  Landeck,  on  the  29th  of  August, 
I  learned  that  the  nearest  glacier  was  that  adjacent  to  the 
Gebatsch  Alp,  at  the  head  of  the  Kaunserthal ;  and  on 
the  following  morning  I  was  on  my  way  towards  this  valley. 
I  sought  to  obtain  a  guide  at  Kaltebrunnen,  but  failed ;  and 
afterwards  walked  to  the  little  hamlet  of  Feuchten,  where 
I  put  up  at  a  very  lowly  inn.  My  host,  I  believe,  had 
never  seen  an  Englishman,  but  he  had  heard  of  such,  and 
remarked  to  me  in  his  patois  with  emphasis,  "  Die  Eng- 
lander  sind  die  kiihnste  Leute  in  dieserWelt."  Through 
his  mediation  I  secured  a  chamois-hunter,  named  Johann 
Auer,  to  be  my  guide,  and  next  morning  I  started  with  this 
man  up  the  valley.  The  sun,  as  we  ascended,  smote  the 
earth  and  us  with  great  power ;  high  mountains  flanked 
us  on  either  side,  while  in  front  of  us,  closing  the  view,  was 
the  mass  of  the  Weisskugel,  covered  with  snow.  At  three 


24  THE   GEBATSCH  ALP.  [1856. 

o'clock  we  came  in  sight  of  the  glacier,  and  soon  afterwards 
I  made  the  acquaintance  of  the  Senner  or  cheesemakers 
of  the  Gebatsch  Alp. 

The  chief  of  these  was  a  fine  tall  fellow,  with  free,  frank 
countenance,  which,  however,  had  a  dash  of  the  mountain 
wild  ness  in  it.  His  feet  were  bare,  he  wore  breeches,  and 
fragments  of  stockings  partially  covered  his  legs,  leaving 
a  black  zone  between  the  upper  rim  of  the  sock  and  the 
breeches.  His  feet  and  face  were  of  the  same  swarthy 
hue  ;  still  he  was  handsome,  and  in  a  measure  pleasant 
to  look  upon.  He  asked  me  what  he  could  cook  for  me, 
and  I  requested  some  bread  and  milk ;  the  former  was  a 
month  old,  the  latter  was  fresh  and  delicious,  and  on  these 
I  fared  sumptuously.  I  went  to  the  glacier  afterwards 
with  my  guide,  and  remained  upon  the  ice  until  twilight, 
when  we  returned,  guided  by  no  path, 'but  passing  amid 
crags  grasped  by  the  gnarled  roots  of  the  pine,  through 
green  dells,  and  over  bilberry  knolls  of  exquisite  colour- 
ing. My  guide  kept  in  advance  of  me  singing  a  Tyrolese 
melody,  and  his  song  and  the  surrounding  scene  revived 
and  realised  all  the  impressions  of  my  boyhood  regarding 
the  Tyrol. 

Milking  was  over  when  we  returned  to  the  chalet,  which 
now  contained  four  men  exclusive  of  myself  and  my  guide. 
A  fire  of  pine  logs  was  made  upon  a  platform  of  stone, 
elevated  three  feet  above  the  floor ;  there  was  no  chimney, 
as  the  smoke  found  ample  vent  through  the  holes  and 
fissures  in  the  sides  and  roof.  The  men  were  all  intensely 
sunburnt,  the  legitimate  brown  deepening  into  black  with 
beard  and  dirt.  The  chief  senner  prepared  supper,  break- 
ing eggs  into  a  dish,  and  using  his  black  fingers  to  empty 
the  shell  when  the  albumen  was  refractory.  A  fine 
erect  figure  he  was  as  he  stood  in  the  glowing  light  of  the 
fire.  All  the  men  were  smoking,  and  now  and  then  a 
brand  was  taken  from  the  fire  to  light  a  renewed  pipe,  and 


1856.]  AN  ALPINE   CHALET.  25 

a  ruddy  glare  flung  thereby  over  the  wild  countenance  of 
the  smoker.  In  one  corner  of  the  chalet,  and  raised  high 
above  the  ground,  was  a  large  bed,  covered  with  clothes 
of  the  most  dubious  black-brown  hue ;  at  one  end  was  a 
little  water-wheel  turned  by  a  brook,  which  communi- 
cated motion  to  a  churndash  which  made  the  butter.  The 
beams  and  rafters  were  covered  with  cheeses,  drying  in 
the  warm  smoke.  The  senner,  at  my  request,  showed  me 
his  storeroom,  and  explained  to  me  the  process  of  making 
cheese,  its  interest  to  me  consisting  in  its  bearing  upon 
the  question  of  slaty  cleavage.  Three  gigantic  masses  of 
butter  were  in  the  room,  and  I  amused  my  host  by  calling 
them  butter-glaciers.  Soon  afterwards  a  bit  of  cotton  was 
stuck  in  a  lump  of  grease,  which  was  placed  in  a  lantern, 
and  the  wick  ignited ;  the  chamois-hunter  took  it,  and  led 
the  way  to  our  resting-place,  I  having  previously  declined 
a  good-natured  invitation  to  sleep  in  the  big  black  bed 
already  referred  to. 

There  was  a  cowhouse  near  the  chalet,  and  above  it, 
raised  on  pillars  of  pine,  and  approached  by  a  ladder,  was 
a  loft,  which  contained  a  quantity  of  dry  hay :  this  my 
guide  shook  to  soften  the  lumps,  and  erected  an  eminence 
for  my  head.  I  lay  down,  drawing  my  plaid  over  me,  but 
Auer  affirmed  that  this  would  not  be  a  sufficient  protec- 
tion against  the  cold  ;  he  therefore  piled  hay  upon  me  to 
the  shoulders,  and  proposed  covering  up  my  head  also. 
This,  however,  I  declined,  though  the  biting  coldness  of 
the  air,  which  sometimes  blew  in  upon  us,  afterwards 
proved  to  me  the  wisdom  of  the  suggestion.  Having  set 
me  right,  my  chamois-hunter  prepared  a  place  for  himself, 
and  soon  his  heavy  breathing  informed  me  that  he  was 
in  a  state  of  bliss  which  I  could  only  envy.  One  by  one 
the  stars  crossed  the  apertures  in  the  roof.  Once  the 
Pleiades  hung  above  me  like  a  cluster  of  gems ;  I  tried  to 
admire  them,  but  there  was  no  fervour  in  my  admiration. 


26  THE   GEBATSCH   GLACIER.  [1856. 

Sometimes  I  dozed,  but  always  as  this  was  about  to  deepen 
into  positive  sleep  it  was  rudely  broken  by  the  clamour 
of  a  group  of  pigs  which  occupied  the  ground-floor  of  our 
dwelling.  The  object  of  each  individual  of  the  group 
was  to  secure  for  himself  the  maximum  amount  of  heat, 
and  hence  the  outside  members  were  incessantly  trying 
to  become  inside  ones.  It  was  the  struggle  of  radical 
and  conservative  among  the  pachyderms,  the  politics  be- 
ing determined  by  the  accident  of  position. 

I  rose  at  five  o'clock  on  the  1st  of  September,  and  after 
a  breakfast  of  black  bread  and  milk  ascended  the  glacier 
as  far  as  practicable.  We  .once  quitted  it,  crossed  a  pro- 
montory, and  descended  upon  one  of  its  branches,  which 
was  flanked  by  some  fine  old  moraines.  We  here  came 
upon  a  group  of  seven  marmots,  which  with  yells  of  ter- 
ror scattered  themselves  among  the  rocks.  The  points 
of  the  glacier  beyond  my  reach  I  examined  through  a  tel- 
escope ;  along  the  faces  of  the  sections  the  lines  of  strati- 
fication were  clearly  shown ;  and  in  many  places  where 
the  mass  showed  manifest  signs  of  lateral  pressure,  I 
thought  I  could  observe  the  cleavage  passing  through  the 
strata.  The  point,  however,  was  too  important  to  rest 
upon  an  observation  made  from  such  a  distance,  and  I 
therefore  abstained  from  mentioning  it  subsequently.  I 
examined  the  fissures  and  the  veining,  and  noticed  how 
the  latter  became  most  perfect  in  places  where  the  press- 
ure was  greatest.  The  effect  of  oblique  pressure  was  also 
finely  shown  :  at  one  place  the  thrust  of  the  descending 
glacier  was  opposed  by  the  resistance  offered  by  the  side 
of  the  valley,  the  direction  of  the  force  being  oblique  to 
the  side ;  the  consequence  was  a  structure  nearly  parallel 
to  the  valley,  and  consequently  oblique  to  the  thrust 
which  I  believe  to  be  its  cause. 

After  five  hours'  examination  we  returned  to  our  chalet, 
where  we  refreshed  ourselves,  put  our  things  in  order,  and 


1856.]  A  CHAMOIS   ON  THE  ROCKS.  27 

faced  a  nameless  "  Joch,"  or  pass  ;  our  aim  being  to  cross 
the  mountains  into  the  valley  of  Lantaufer,  and  reach 
Graun  that  evening.  After  a  rough  ascent  over  the  alp 
we  came  to  the  dead  crag,  where  the  weather  had  broken 
up  the  mountains  into  ruinous  heaps  of  rock  and  shingle. 
We  reached  the  end  of  a  glacier,  the  ice  of  which  was 
covered  by  sloppy  snow,  and  at  some  distance  up  it  came 
upon  an  islet  of  stones  and  debris,  where  we  paused  to 
rest  ourselves.  My  guide,  as  usual,  ranged  over  the  sum- 
mits with  his  telescope,  and  at  length  exclaimed,  "  I  see  a 
chamois."  The  creature  stood  upon  a  cliff  some  hundreds 
of  yards  to  our  left,  and  seemed  to  watch  our  movements. 
It  was  a  most  graceful  animal,  and  its  life  and  beauty 
stood  out  in  forcible  antithesis  to  the  surrounding  sav- 
agery and  death. 

On  the  steep  slopes  of  the  glacier  I  was  assisted  by  the 
hand  of  my  guide.  In  fact,  on  this  day  I  deemed  places 
dangerous,  and  dreaded  them  as  such,  which  subsequent 
practice  enabled  me  to  regard  with  perfect  indifference  ; 
so  much  does  what  we  call  courage  depend  upon  habit,  or 
on  the  fact  of  knowing  that  we  have  really  nothing  to  fear. 
Doubtless  there  are  times  when  a  climber  has  to  make  up 
his  mind  for  very  unpleasant  possibilities,  and  even  gather 
calmness  from  the  contemplation  of  the  worst ;  but  in 
most  cases  I  should  say  that  his  courage  is  derived  from 
the  latent  feeling  that  the  chances  of  safety  are  immensely 
in  his  favour. 

After  a  tough  struggle  we  reached  the  narrow  row  of 
crags  which  form  the  crest  of  the  pass,  and  looked  into 
the  world  of  mountain  and  cloud  on  the  other  side.  The 
scene  was  one  of  stern  grandeur,  —  the  misty  lights  and 
deep  cloud-glooms  being  so  disposed  as  to  augment  the 
impression  of  vastness  which  the  scene  conveyed.  The 
breeze  at  the  summit  was  exceedingly  keen,  but  it  gave 
our  muscles  tone,  and  we  sprang  swiftly  downward 


28  PASSAGE   OF  A  JOCH.  [1856. 

through  the  yielding  de*bris  which  here  overlies  the  moun- 
tain, and  in  which  we  sometimes  sank  to  the  knees. 
Lower  down  we  came  once  more  upon  the  ice.  The 
glacier  had  at  one  place  melted  away  from  its  bounding 
cliff,  which  rose  vertically  to  our  right,  while  a  wall  of 
ice  60  or  80  feet  high  was  on  our  left.  Between  both  was 
a  narrow  passage,  the  floor  of  which  was  snow,  which 
I  knew  to  be  hollow  beneath :  my  companion,  however, 
was  in  advance  of  me,  and  he  being  the  heavier  man, 
where  he  trod  I  followed  without  hesitation.  On  turn- 
ing an  angle  of  the  rock  I  noticed  an  expression  of 
concern  upon  his  countenance,  and  he  muttered  audibly, 
"  I  did  not  expect  this."  The  snow-floor  had,  in  fact, 
given  way,  and  exposed  to  view  a  clear  green  lake,  one 
boundary  of  which  was  a  sheer  precipice  of  rock,  and  the 
other  the  aforesaid  wall  of  ice  ;  the  latter,  however,  curved 
a  little  at  its  base,  so  as  to  form  a  short  steep  slope  which 
overhung  the  water.  My  guide  first  tried  the  slope  alone  ; 
biting  the  ice  with  his  shoe-nails,  and  holding  on  by  the 
spike  of  his  baton,  he  reached  the  other  side.  He  then 
returned,  and,  divesting  myself  of  all  superfluous  clothes, 
as  a  preparation  for  the  plunge  which  I  fully  expected,  I 
also  passed  in  safety.  Probably  the  consciousness  that  I 
had  water  to  fall  into  instead  of  pure  space,  enabled  me 
to  get  across  without  anxiety  or  mischance  ;  but  had  I, 
like  rny  guide,  been  unable  to  swim,  my  feelings  would 
have  been  far  different. 

This  accomplished,  we  went  swiftly  down  the  valley, 
and  the  more  I  saw  of  my  guide,  the  more  I  liked  him. 
He  might,  if  he  wished,  have  made  his  day's  journey 
shorter  by  stopping  before  he  reached  Graun,  but  he 
would  not  do  so.  Every  word  he  said  to  me  regarding 
distances  was  true,  and  there  was  not  the  slightest  de- 
sire shown  to  magnify  his  own  labour.  I  learnt  by  mere 
accident  that  the  day's  work  had  cut  up  his  feet,  but  his 


1856.]  THE   STELVIO.  29 

cheerfulness  and  energy  did  not  bate  a  jot  till  he  had 
landed  me  in  the  Black  Eagle  at  Graun.  Next  morning 
he  came  to  my  room,  and  said  that  he  felt  sufficiently  re- 
freshed to  return  home.  I  paid  him  what  I  owed  him, 
when  he  took  my  hand,  and,  silently  bending  down  his 
head,  kissed  it ;  then,  standing  erect,  he  stretched  forth 
his  right  hand,  which  I  grasped  firmly  in  mine,  and  bade 
him  farewell ;  and  thus  I  parted  from  Johann  Auer,  my 
brave  and  truthful  chamois-hunter. 

On  the  following  day  I  met  Dr.  Frankland  in  the  Fin- 
stermuntz  pass,  and  that  night  we  bivouacked  together  at 
Mais.  Heavy  rain  fell  throughout  the  night,  but  it  came 
from  a  region  high  above  that  of  liquidity.  It  was  first 
snow,  which,  as  it  descended  through  the  warmer  strata 
of  the  atmosphere,  was  reduced  to  water.  Overhead,  in 
the  air,  might  be  traced  a  surface,  below  which  the  pre- 
cipitate was  liquid,  above  which  it  was  solid ;  and  this 
surface,  intersecting  the  mountains  which  surround  Mais, 
marked  upon  them  a  beautifully-defined  snow-line,  below 
which  the  pines  were  dark  and  the  pastures  green,  but 
above  which  pines  and  pastures  and  crags  were  covered 
with  the  freshly-fallen  snow. 

On  the  2d  of  September  we  crossed  the  Stelvio.  The 
brown  cone  of  the  well-known  Madatschspitze  was  clear, 
but  the  higher  summits  were  clouded,  and  the  fragments 
of  sunshine  which  reached  the  lower  world  wandered  like 
gleams  of  fluorescent  light  over  the  glaciers.  Near  the 
snow-line  the  partial  melting  of  the  snow  had  rendered  it 
coarsely  granular,  but  as  we  ascended  it  became  finer,  and 
the  light  emitted  from  its  cracks  and  cavities  a  pure  and 
deep  blue.  When  a  staff  was  driven  into  the  snow  low 
down  the  mountain,  the  colour  of  the  light  in  the  orifice 
was  scarcely  sensibly  blue,  but  higher  up  this  increased  in 
a  wonderful  degree,  and  at  the  summit  the  effect  was  mar- 
vellous. I  struck  my  staff  into  the  snow,  and  turned  it 


30  COLOUR  OF  FRESH  SNOW.  [1856. 

round  and  round ;  the  surrounding  snow  cracked  repeat- 
edly, and  flashes  of  blue  light  issued  from  the  fissures. 
The  fragments  of  snow  that  adhered  to  the  staff  were,  by 
contrast,  of  a  beautiful  pink  yellow,  so  that,  on  moving 
the  staff  with  such  fragments  attached  to  it  up  and  down, 
it  was  difficult  to  resist  the  impression  that  a  pink  flame 
was  ascending  and  descending  in  the  hole.  As  we  went 
down  the  other  side  of  the  pass,  the  effect  became  more 
and  more  feeble,  until,  near  the  snow-line,  it  almost  wholly 
disappeared. 

We  remained  that  night  at  the  baths  of  Bormio,  but, 
the  following  afternoon  being  fine,  we  wished  to  avail  our- 
selves of  the  fair  weather  to  witness  the  scene  from  the 
summit  of  the  pass.  Twilight  came  on  before  we  reached 
Santa  Maria,  but  a  gorgeous  orange  overspread  the  west- 
ern horizon,  from  which  we  hoped  to  derive  sufficient  light. 
It  was  a  little  too  late  when  we  reached  the  top,  but  still 
the  scene  was  magnificent.  A  multitude  of  mountains 
raised  their  crowns  towards  heaven,  while  above  all  rose 
the  snow-white  cone  of  the  Ortler.  Far  into  the  valley 
the  giant  stretched  his  granite  limbs,  until  they  were  hid 
from  us  by  darkness.  As  this  deepened,  the  heavens  be- 
came more, and  more  crowded  with  stars,  which  blazed  like 
gems  over  the  heads  of  the  mountains.  At  times  the 
silence  was  perfect,  unbroken  save  by  the  crackling  of  the 
frozen  snow  beneath  our  own  feet ;  while  at  other  times  a 
breeze  would  swoop  down  upon  us,  keen  and  hostile,  scat- 
tering the  snow  from  the  roofs  of  the  wooden  galleries  in 
frozen  powder  over  iis.  Long  after  night  had  set  in,  a 
ghastly  gleam  rested  upon  the  summit  of  the  Ortler,  while 
the  peaks  in  front  deepened  to  a  dusky  neutral  tint,  the 
more  distant  ones  being  lost  in  gloom.  We  descended  at 
a  swift  pace  to  Trafoi,  which  we  reached  before  11  P.  M. 

Meran  was  our  next  resting-place,  whence  we  turned 
through  the  Schnalzerthal  to  Unserfrau,  and  thence  over 


1856.]  SINGULAR  HAIL-STORM.  31 

the  Hochjoch  to  Fend.  From  a  religious  procession  we 
took  a  guide,  who,  though  partly  intoxicated,  did  his  duty 
well.  Before  reaching  the  summit  of  the  pass  we  were 
assailed  by  a  violent  hailstorm,  each  hailstone  being  a 
frozen  cone  with  a  rounded  end.  Had  not  their  motion 
through  the  air  something  to  do  with  the  shape  of  these 
hailstones  ?  The  theory  of  meteorites  now  generally  ac- 
cepted is  that  they  are  small  planetary  bodies  drawn  to 
the  earth  by  gravity,  and  brought  to  incandescence  by 
friction  against  the  earth's  atmosphere.  Such  a  body 
moving  through  the  atmosphere  must  have  condensed  hot 
air  in  front  of  it,  and  rarefied  cool  air  behind  it ;  and  the 
same  is  true  to  a  small  extent  of  a  hailstone.  This  distri- 
bution of  temperature  must,  I  imagine,  have  some  influ- 
ence on  the  shape  of  the  stone.  Possibly  also  the  strati- 
fied appearance  of  some  hailstones  may  be  connected  witli 
this  action.* 

The  hail  ceased  and  the  heights  above  us  cleared  as  we 
ascended.  At  the  top  of  the  pass  we  found  ourselves  on 
the  verge  of  a  great  nevS,  which  lay  between  two  ranges 
of  summits,  sloping  down  to  the  base  of  each  range  from 
a  high  and  rounded  centre :  a  wilder  glacier  scene  I  have 
scarcely  witnessed.  Wishing  to  obtain  a  more  perfect 
view  of  the  region,  I  diverged  from  the  track  followed  by 
Dr.  Frankland  and  the  guide,  and  climbed  a  ridge  of  snow 

*  I  take  the  following  account  of  a  grander  storm  of  the  above  character 
from  Hooker's  "Himalayan  Journals/'  vol.  ii.  p.  405. 

"On  the  20th  (March,  1849)  we  had  a  change  in  the  weather;  a  violent 
storm  from  the  southwest  occurred  at  noon,  with  hail  of  a  strange  form,  the 
stones  being  sections  of  hollow  spheres,  half  an  inch  across  and  upwards, 
formed  of  cones  with  truncated  apices  and  convex  bases :  these  cones  were 
aggregated  together  with  their  bases  outwards.  The  large  masses  were  fol- 
lowed by  a  shower  of  the  separate  conical  pieces,  and  that  by  heavy  rain. 
On  the  mountains  this  storm  was  most  severe  j  the  stones  lay  at  Dorjiling 
for  seven  clays,  congealed  into  masses  of  ice  several  feet  long  and  a  foot 
thick  in  sheltered  places :  at  Purneah,  fifty  miles  south,  stones  one  and  two 
inches  across  fell,  probably  as  whole  spheres." 


82  THE   HOCHJOCH  AND  FEND.  [1856. 

about  half  a  mile  to  the  right  of  them.  A  glorious  ex- 
panse was  before  me,  stretching  itself  in  vast  undulations, 
and  heaping  itself  here  and  there  into  mountainous  cones, 
white  and  pure,  with  the  deep  blue  heaven  behind  them. 
Here  I  had  my  first  experience  of  hidden  crevasses,  and 
to  my  extreme  astonishment  once  found  myself  in  the  jaws 
of  a  fissure  of  whose  existence  I  had  not  the  slightest 
notice.  Such  accidents  have  often  occurred  to  me  since, 
but  the  impression  made  by  the  first  is  likely  to  remain 
the  strongest.  It  was  dark  when  we  reached  the  wretched 
Wirthshaus  at  Fend,  where,  badly  fed,  badly  lodged,  and 
disturbed  by  the  noise  of  innumerable  rats,  we  spent  the 
night.  Thus  ended  my  brief  glacier  expedition  of  1856  ; 
and  on  the  observations  then  made,  and  on  subsequent 
experiments,  was  founded  a  paper  presented  to  the  Royal 
Society  by  Mr.  Huxley  and  myself. 


1857.J  THE  LAKE   OF  GENEVA.  33 

EXPEDITION  OF   1857. 
THE   LAKE   OF   GENEVA. 

(4.) 

THE  time  occupied  in  the  observations  of  1856  embraced 
about  five  whole  days  ;  and  though  these  days  were  labo- 
rious and  instructive,  still  so  short  a  time  proved  to  be 
wholly  incommensurate  with  the  claims  of  so  wide  a  pro- 
blem. During  the  subsequent  experimental  treatment  of 
the  subject,  I  had  often  occasion  to  feel  the  incompleteness 
of  my  knowledge,  and  hence  arose  the  desire  to  make  a 
second  expedition  to  the  Alps,  for  the  purpose  of  expand- 
ing, fortifying,  or,  if  necessary,  correcting  first  impressions. 

On  Thursday,  the  9th  of  July,  1857, 1  found  myself  upon 
the  Lake  of  Geneva,  proceeding  towards  Vevey.  I  had 
long  wished  to  see  the  waters  of  this  renowned  inland  sea, 
the  colour  of  which  is  perhaps  more  interesting  to  the  man 
of  science  than  to  the  poets  who  have  sung  about  it.  Long 
ago  its  depth  of  blue  excited  attention,  but  no  systematic 
examination  of  the  subject  has,  so  far  as  1  know,  been 
attempted.  It  may  be  that  the  lake  simply  exhibits  the 
colour  of  pure  water.  Ice  is  blue,  and  it  is  reasonable  to 
suppose  that  the  liquid  obtained  from  the  fusion  of  ice  is 
of  the  same  colour ;  but  still  the  question  presses,  "  Is 
the  blue  of  the  Lake  of  Geneva  to  be  entirely  accounted 
for  in  this  way  ?  "  The  attempts  which  have  been  made 
to  explain  it  otherwise,  show  that  at  least  a  doubt  exists  as 
to  the  sufficiency  of  the  above  explanation. 

It  is  only  in  its  deeper  portions  that  the  colour  of  the 
lake  is  properly  seen.  Where  the  bottom  comes  into  view 
the  pure  effect  of  the  water  is  disturbed ;  but  where  the 
3 


34  BLUENESS   OF  THE  WATER.  [1857. 

water  is  deep  the  colour  is  deep :  between  Rolle  and 
Nyon  for  example,  the  blue  is  superb.  Where  the  blue 
was  deepest,  however,  it  gave  me  the  impression  of  turbidity 
rather  than  of  deep  transparency.  At  the  upper  portion  of 
the  lake  the  water  through  which  the  steamer  passed  was 
of  a  blue  green.  Wishing  to  see  the  place  where  the  Rhone 
enters  the  lake,  I  walked  on  the  morning  of  the  10th  from 
Villeneuve  to  Novelle,  and  thence  through  the  woods  to 
the  river  side.  Proceeding  along  an  embankment,  raised 
to  defend  the  adjacent  land  from  the  incursions  of  the 
river,  an  hour  brought  me  to  the  place  where  it  empties 
itself  into  the  lake.  The  contrast  between  the  two  waters 
was  very  great :  the  river  was  almost  white  with  the  finely 
divided  matter  which  it  held  in  suspension  ;  while  the  lake 
at  some  distance  was  of  a  deep  ultramarine. 

The  lake  in  fact  forms  a  reservoir  where  the  particles 
held  in  suspension  by  the  river  have  time  to  subside,  and 
its  waters  to  become  pure.  The  subsidence  of  course  takes 
place  most  copiously  at  the  head  of  the  lake  ;  and  here 
the  deposit  continues  to  form  new  land,  adding  year  by 
year  to  the  thousands  of  acres  which  it  has  already  left 
behind  it,  and  invading  more  and  more  the  space  occupied 
by  the  water.  Innumerable  plates  of  mica  spangled  the 
fine  sand  which  the  river  brought  down,  and  these,  mixing 
with  the  water,  and  flashing  like  minute  mirrors  as  the 
sun's  rays  fell  upon  them,  gave  the  otherwise  muddy 
stream  a  silvery  appearance.  Had  I  an  opportunity  I 
would  make  the  following  experiments :  — 

(a.)  Compare  the  colour  of  the  light  transmitted  by  a 
column  of  the  lake  water  fifteen  feet  long  with  that  trans- 
mitted by  a  second  column,  of  the  same  length,  derived 
from  the  melting  of  freshly  fallen  mountain  snow. 

(6.)  Compare  in  the  same  manner  the  colour  of  the  or- 
dinary water  of  the  lake  with  that  of  the  same  water  after 
careful  distillation. 


1857.] 


ATMOSPHERIC  REFRACTION. 


35 


(c.)  Strictly  examine  whether  the  light  transmitted  by 
the  ordinary  water  contains  an  excess  of  red  over  that 
transmitted  by  the  distilled  water :  this  latter  point,  as 
will  be  seen  farther  on,  is  one  of  peculiar  interest. 

The  length  is  fixed  at  fifteen  feet,  because  I  have  found 
this  length  extremely  efficient  in  similar  experiments. 

On  returning  to  the  pier  at  Yilleneuve,  a  peculiar  flick- 
ering motion  was  manifest  upon  the  surface  of  the  dis- 
tant portions  of  the  lake,  and  I  soon  noticed  that  the 
coast  line  was  inverted  by  atmospheric  refraction.  It 
required  a  long  distance  to  produce  the  effect :  no  trace 
of  it  was  seen  about  the  Castle  of  Chillon,  but  at  Vevey 
and  beyond  it,  the  whole  coast  was  clearly  inverted ;  and 
the  houses  on  the  margin  of  the  lake  were  also  imaged  to 
a  certain  height.  Two  boats  at  a  considerable  distance  pre- 
sented the  appearance  sketched  in  Figs.  3  and  4  ;  the  hull 


Fig.  3. 


Fig.  4. 


of  each,  except  a  small  portion  at  the  end,  was  invisible, 
but  the  sails  seemed  lifted  up  high  in  the  air,  with  their 
inverted  images  below ;  as  the  boats  drew  nearer,  the 
hulls  appeared  inverted,  the  apparent  height  of  the  vessel 
above  the  surface  of  the  lake  being  thereby  nearly  doubled, 


36  MIRAGE.  [1857. 

while  the  sails  and  higher  objects,  in  these  cases,  were 
almost  completely  cut  away.  When  viewed  through  a 
telescope  the  sensible  horizon  of  the  lake  presented  a  bil- 
lowy tumultuous  appearance,  fragments  being  incessantly 
detached  from  it  and  suspended  in  the  air. 

The  explanation  of  this  effect  is  the  same  as  that  of  the 
mirage  of  the  desert,  which  may  be  found  in  almost  any 
book  on  physics,  and  which  so  tantalized  the  French 
soldiers  in  Egypt.  They  often  mistook  this  aerial  inversion 
for  the  reflection  from  a  lake,  and  on  trial  found  hot  and 
sterile  sand  at  the  place  where  they  expected  refreshing 
waters.  The  effect  was  shown  by  Monge,  one  of  the 
learned  men  who  accompanied  the  expedition,  to  be  due 
to  the  total  reflection  of  very  oblique  rays  at  the  upper 
surface  of  the  layer  of  rarefied  air  which  was  nearest  to 
the  heated  earth.  A  sandy  plain,  in  the  early  part  of  the 
day,  is  peculiarly  favourable  for  the  production  of  such 
effects  ;  and  on  the  extensive  flat  strand  which  stretches 
between  Mont  St.  Michel  and  the  coast  adjacent  to 
Avranches  in  Normandy,  I  have  noticed  Mont  Tom- 
beline  reflected  as  if  glass  instead  of  sand  surrounded  it 
and  formed  its  mirror. 


1857.]  CHAMOUNI  AND   THE  MONTANVERT.  37 

CHAMOUNI  AND   THE   MONTANVERT. 
(5.) 

ON  the  evening  of  the  12th  of  July  I  reached  Chamouni ; 
the  weather  was  not  quite  clear,  but  it  was  promising ; 
white  cumuli  had  floated  round  Mont  Blanc  during  the 
day,  but  these  diminished  more  and  more,  and  the  light  of 
the  setting  sun  was  of  that  lingering  rosy  hue  which  bodes 
good  weather.  Two  parallel  beams  of  a  purple  tinge  were 
drawn,  by  the  shadows  of  the  adjacent  peaks,  straight  across 
the  Glacier  des  Bossons,  and  the  Glacier  des  Pelerins  was 
also  steeped  for  a  time  in  the  same  purple  light.  Once 
when  the  surrounding  red  illumination  was  strong,  the 
shadows  of  the  Grands  Mulcts  falling  upon  the  adjacent 
snow  appeared  of  a  vivid  green. 

This  green  belonged  to  the  class  of  subjective  colours,  or 
colours  produced  by  contrast,  about  which  a  volume  might 
be  written.  The  eye  received  the  impression  of  green, 
but  the  colour  was  not  external  to  the  eye.  Place  a  red 
wafer  on  white  paper,  and  look  at  it  intently,  it  will  be 
surrounded  in  a  little  time  by  a  green  fringe :  move  the 
wafer  bodily  away,  and  the  entire  space  which  it  occupied 
upon  the  paper  will  appear  green.  A  body  may  have  its 
proper  colour  entirely  masked  in  this  way.  Let  a  red 
wafer  be  attached  to  a  piece  of  red  glass,  and  from  a 
moderately  illuminated  position  let  the  sky  be  regarded 
through  the  glass  ;  the  wafer  will  appear  of  a  vivid  green. 
If  a  strong  beam  of  light  be  sent  through  a  red  glass  and 
caused  to  fall  upon  a  screen,  which  at  the  same  time  is 
moderately  illuminated  by  a  separate  source  of  white  light, 
an  opaque  body  placed  in  the  path  of  the  beam  will  cast  a 
green  shadow  upon  the  screen,  which  may  be  seen  by  seve- 


38  COLOURED  SHADOWS.  [1857. 

ral  hundred  persons  at  once.  If  a  blue  glass  be  used, 
the  shadow  will  be  yellow,  which  is  the  complementary 
colour  to  blue. 

When  we  suddenly  pass  from  open  sunlight  to  a  mode- 
rately illuminated  room,  it  appears  dark  at  first,  but  after 
a  little  time  the  eye  regains  the  power  of  seeing  objects  dis- 
tinctly. Thus  one  effect-of  light  upon  the  eye  is  to  render 
it  less  sensitive,  and  light  of  any  particular  colour  falling 
upon  the  eye  blunts  its  appreciation  of  that  colour.  Let  us 
apply  this  to  the  shadow  upon  the  screen.  This  shadow 
is  moderately  illuminated  by  a  jet  of  white  light ;  but  the 
space  surrounding  it  is  red,  the  effect  of  which  upon 
the  eye  is  to  blind  it  in  some  degree  to  the  perception  of 
red.  Hence,  when  the  feeble  white  light  of  the  shadow 
reaches  the  eye,  the  red  component  of  this  light  is,  as  it 
were,  abstracted  from  it,  and  the  eye  sees  the  residual 
colour,  which  is  green.  A  similar  explanation  applies  to 
the  shadows  of  the  Grands  Millets. 

On  the  13th  of  July  I  was  joined  by  my  friend  Mr. 
Thomas  Hirst,  and  on  the  14th  we  examined  together  the 
end  of  the  Mer  de  Glace.  In  former  times  the  whole  volume 
of  the  Arveiron  escaped  from  beneath  the  ice  at  the 
end  of  the  glacier,  forming  a  fine  arch  at  its  place  of 
issue.  This  year  a  fraction  only  of  the  water  thus  found 
egress  ;  the  greater  portion  of  it  escaping  laterally  from  the 
glacier  at  the  summit  of  the  rocks  called  Les  Motets,  down 
which  it  tumbled  in  a  fine  cascade.  The  vault  at  the 
end  of  the  glacier  was  nevertheless  respectable,  and  rather 
tempting  to  a  traveller  in  search  of  information  regard- 
ing the  structure  of  the  ice.  Perhaps,  however,  Nature 
meant  to  give  me  a  friendly  warning  at  the  outset,  for, 
while  speculating  as  to  the  wisdom  of  entering  the  cavern, 
it  suddenly  gave  way,  and,  with  a  crash  which  rivalled 
thunder,  the  roof  strewed  itself  in  ruins  upon  the  floor. 

Many  years  ago  I  had  read  with  delight  Coleridge's 


1857.]  SUNRISE  AT  CHAMOUNI.  39 

poem  entitled  <  Sunrise  in  the  Valley  of  Chamouni,'  and 
to  witness  in  all  perfection  the  scene  described  by  the  poet, 
I  waited  at  Chamouni  a  day  longer  than  was  otherwise 
necessary.  On  the  morning  of  Wednesday,  the  15th  of  July, 
I  rose  before  the  sun ;  Mont  Blanc  and  his  wondrous  staff  of 
Aiguilles  were  without  a  cloud  ;  eastward  the  sky  was  of  a 
pale  orange  which  gradually  shaded  off  to  a  kind  of  rosy 
violet,  and  this  again  blended  by  imperceptible  degrees 
with  the  deep  zenithal  blue.  The  morning  star  was  still 
shining  to  the  right,  and  the  moon  also  turned  a  pale  face 
towards  the  rising  day.  The  valley  was  full  of  music ; 
from  the  adjacent  woods  issued  a  gush  of  song,  while  the 
sound  of  the  Arve  formed  a  suitable  bass  to  the  shriller 
melody  of  the  birds.  The  mountain  rose  for  a  time  cold  and 
grand,  with  no  apparent  stain  upon  his  snows.  Suddenly 
the  sunbeams  struck  his  crown  and  converted  it  into  a 
boss  of  gold.  For  some  time  it  remained  the  only  gilded 
summit  in  view,  holding  communion  with  the  dawn  while 
all  the  others  waited  in  silence.  These,  in  the  order  of 
their  heights,  came  afterwards,  relaxing,  as  the  sunbeams 
struck  each  in  succession,  into  a  blush  and  smile. 

On  the  same  day  we  had  our  luggage  transported  to  the 
Montanvert,  while  we  clambered  along  the  lateral  moraine 
of  the  glacier  to  the  Chapeau.  The  rocks  alongside  the 
glacier  were  beautifully  scratched  and  polished,  and  1  paid 
particular  attention  to  them,  for  the  purpose  of  furnishing 
myself  with  a  key  to  ancient  glacier  action.  The  scene 
to  my  right  was  one  of  the  most  wonderful  I  had  ever  wit- 
nessed. Along  the  entire  slope  of  the  Glacier  de  Bois,  the 
ice  was  cleft  and  riven  into  the  most  striking  and  fantastic 
forms.  It  had  not  yet  suffered  much  from  the  wasting  in- 
fluence of  the  summer  weather,  but  its  towers  and  minarets 
sprang  from  the  general  mass  with  clean  chiselled  outlines. 
Some  stood  erect,  others  leaned,  while  the  white  debris, 
strewn  here  and  there  over  the  glacier,  showed  where  the 


40  GLACIER   DES   BOIS.  [1857. 

wintry  edifices  had  fallen,  breaking  themselves  to  pieces, 
and  grinding  the  masses  on  which  they  fell  to  powder. 
Some  of  them  gave  way  during  our  inspection  of  the  place, 
and  shook  the  valley  with  the  reverberated  noise  of  their 
fall.  I  endeavoured  to  get  near  them,  but  failed ;  the 
chasms  at  the  margin  of  the  glacier  were  too  dangerous, 
and  the  stones  resting  upon  the  heights  too  loosely  poised, 
to  render  persistence  in  the  attempt  excusable. 

We  subsequently  crossed  the  glacier  to  the  Montanvert, 
and  I  formally  took  up  my  position  there.  The  rooms  of 
the  hotel  were  separated  from  each  other  by  wooden  par- 
titions merely,  and  thus  the  noise  of  early  risers  in  one 
room  was  plainly  heard  in  the  next.  For  the  sake  of 
quiet,  therefore,  I  had  my  bed  placed  in  the  chdteau  next 
door, —  a  little  octagonal  building  erected  by  some 
kind  and  sentimental  Frenchman,  and  dedicated  "  a  la 
Nature"  My  host  at  first  demurred,  thinking  the  place 
not  "propre"  but  I  insisted,  and  he  acquiesced.  True 
the  stone  floor  was  dark  with  moisture,  and  on  the  walls  a 
glistening  was  here  and  there  observable,  which  suggested 
rheumatism,  and  other  penalties,  but  I  had  had  no  expe- 
rience of  rheumatism,  and  trusted  to  the  strength  which 
mountain  air  and  exercise  were  sure  to  give  me,  for 
power  to  resist  its  attacks.  Moreover,  to  dispel  some  of 
the  humidity,  it  was  agreed  that  a  large  pine  fire  should 
be  made  there  on  necessary  occasions. 

Though  singularly  favoured  on  the  whole,  still  our  resi- 
dence at  the  Montanvert  was  sufficiently  long  to  give  us 
specimens  of  all  kinds  of  weather ;  and  thus  my  chateau 
derived  an  interest  from  the  mutations  of  external  nature. 
Sometimes  no  breath  disturbed  the  perfect  serenity  of  the 
night,  and  the  moon,  set  in  a  black-blue  sky,  turned  a  face 
of  almost  supernatural  brightness  to  the  mountains,  while 
in  her  absence  the  thick-strewn  stars  alone  flashed  and 
twinkled  through  the  transparent  air.  Sometimes  dull 


1857.]  QUARTERS  AT   THE  MONTANVERT.  41 

dank  fog  choked  the  valley,  and  heavy  rain  plashed  upon 
the  stones  outside.  On  two  or  three  occasions  we  were 
favoured  by  a  thunderstorm,  every  peal  of  which  broke 
into  a  hundred  echos,  while  the  seams  of  lightning  which 
ran  through  the  heavens  produced  a  wonderful  intermit- 
tence  of  gloom  and  glare.  And  as  I  sat  within,  musing 
on  the  experiences  of  the  day,  with  my  pine-logs  crackling, 
and  the  ruddy  fire-light  gleaming  over  the  walls,  and  lend- 
ing animation  to  the  visages  sketched  upon  them  with 
charcoal  by  the  guides,  I  felt  that  my  position  was  in 
every  way  worthy  of  a  student  of  nature. 


42  A  EIVEU  OF  ICE.  [1857. 


THE   MER   DE    GLACE. 
(6.) 

THE  name  "  Mer  de  Glace "  has  doubtless  led  many 
who  have  never  seen  this  glacier  to  a  totally  erroneous  con- 
ception of  its  character.  Misled  probably  by  this  term,  a 
distinguished  writer,  for  example,  defines  a  glacier  to  be 
a  sheet  of  ice  spread  out  upon  the  slope  of  a  mountain  ; 
whereas  the  Mer  de  Glace  is  indeed  a  river,  and  not  a  sea 
of  ice.  But  certain  forms  upon  its  surface,  often  noticed 
and  described,  and  which  I  saw  for  the  first  time  from  the 
window  of  our  hotel  on  the  morning  of  the  16th  of  July, 
suggest  at  once  the  origin  of  the  name.  The  glacier  here 
has  the  appearance  of  a  sea  which,  after  it  had  been  tossed 
by  a  storm,  had  sufficiently  stiffened  into  rest.  The  ridges 
upon  its  surface  accurately  resemble  waves  in  shape,  and 
this  singular  appearance  is  produced  in  the  following 
way. 

Some  distance  above  the  Montanvert  —  opposite  to  the 
Echelets  —  the  glacier,  in  passing  down  an  incline,  is  rent 
by  deep  fissures,  between  each  two  of  which  a  ridge  of 
ice  intervenes.  At  first  the  edges  of  these  ridges  are  sharp 
and  angular,  but  they  are  soon  sculptured  off  by  the  action 
of  the  sun.  The  bearing  of  the  Mer  de  Glace  being  ap- 
proximately north  and  south,  the  sun  at  mid-day  shines 
down  the  glacier,  or  rather  very  obliquely  across  it ;  and 
the  consequence  is,  that  the  fronts  of  the  ridges,  which 
look  downward,  remain  in  shadow  all  the  day,  while  the 
backs  of  the  ridges,  which  look  up  the  glacier,  meet  the 
direct  stroke  of  the  solar  rays.  The  ridges  thus  acted 
upon  have  their  hindmost  angles  wasted  off  and  converted 


1857.1 


FROZEN  WAVES. 


43 


into  slopes  which  represent  the  back  of  a  wave,  while  the 
opposite . side  of  the  ridges,  which  are  protected  from  the 
sun,  preserve  their  steepness,  and  represent  the  front  of 
the  wave.  Fig.  5  will  render  my  meaning  at  once  plain. 


Fig.  5. 


The  dotted  lines  are  intended  to  represent  three  of  the 
ridges  into  which  the  glacier  is  divided,  with  their  inter- 
posed fissures  ;  the  dots  representing  the  boundaries  of 
the  ridges  when  the  glacier  is  first  broken.  The  parallel 
shading  lines  represent  the  direction  of  the  sun's  rays, 
which,  falling  obliquely  upon  the  ridges,  waste  away  the 
right-hand  corners,  and  finally  produce  wave-like  forms. 

We  spent  a  day  or  two  in  making  the  general  acquaint- 
ance of  the  glacier.  On  the  16th  we  ascended  till  we  came 
to  the  rim  of  the  Talefre  basin,  from  which  we  had  a 
good  view  of  the  glacier  system  of  the  region.  The  lami- 
nated structure  of  the  ice  was  a  point  which  particularly 
interested  me  ;  and  as  I  saw  the  exposed  sections  of  the 
neve,  counted  the  lines  of  stratification,  and  compared 
these  with  the  lines  upon  the  ends  of  the  secondary  gla- 


44 


GLACIER  TABLES. 


[1857. 


ciers,  I  felt  the  absolute  necessity  either  of  connecting 
the  veined  structure  with  the  strata  by  a  continuous  chain 
of  observations,  or  of  proving  by  ocular  evidence  that 
they  were  totally  distinct  from  each  other.  I  was  well 
acquainted  with  the  literature  of  the  subject,  but  nothing 
that  I  had  read  was  sufficient  to  prove  what  I  required. 
Strictly  speaking,  nothing  that  had  been  written  upon  the 
subject  rose  above  the  domain  of  opinion,  while  I  felt  that 
without  absolute  demonstration  the  question  would  never 
be  set  at  rest. 

On  this  day  we  saw  some  fine  glacier  tables  ;  flat  masses 
of  rock  raised  high  upon  columns  of  ice :  Fig.  6  is  a 


Fig.  6. 


sketch  of  one  of  the  finest  of  them.  Some  of  them  fell 
from  their  pedestals  while  we  were  near  them,  and  the 
clean  ice-surfaces  which  they  left  behind  sparkled  with  mi- 
nute stars  as  the  small  bubbles  of  air  ruptured  the  film  of 
water  by  which  they  were  overspread.  I  also  noticed  that 
"  petit  bruit  de  crepitation,"  to  which  M.  Agassiz  alludes, 
and  which  he  refers  to  the  rupture  of  the  ice  by  the  ex- 


1857.]  FIRST   SIGHT   OF   THE  DIRT-BANDS.  45 

pansion  of  the  air-bubbles  contained  within  it.  When  I 
first  read  Agassiz's  account  of  it,  I  thought  it  might  be 
produced  by  the  rupture  of  the  minute  air-bubbles  which 
incessantly  escape  from  the  glacier.  This,  doubtless,  pro- 
duces an  effect,  but  there  is  something  in  the  character  of 
the  sound  to  be  referred,  I  think,  to  a  less  obvious  cause, 
which  I  shall  notice  further  on. 

At  six  P.  M.  this  day  I  reached  the  Montanvert ;  and 
the  same  evening,  wrapping  my  plaid  around  me,  I  wan- 
dered up  towards  Charmoz,  and  from  its  heights  observed, 
as  they  had  been  observed  fifteen  years  previously  by  Pro- 
fessor Forbes,  the  dirt-bands  of  the  Mer  de  Glace.  They 
were  different  from  any  I  had  previously  seen,  and  I  felt 
a  strong  desire  to  trace  them  to  their  origin.  Content, 
however,  with  the  performance  of  the  day,  and  feeling 
healthily  tired  by  it,  I  lay  down  upon  the  bilberry  bushes 
and  fell  asleep.  It  was  dark  when  I  awoke,  and  I  expe- 
rienced some  difficulty  and  risk  in  getting  down  from  the 
petty  eminence  referred  to. 

The  illumination  of  the  glacier,  as  remarked  by  Pro- 
fessor Forbes,  has  great  influence  iipon  the  appearance  of 
the  bands ;  they  are  best  seen  in  a  subdued  light  and  I 
think  for  the  following  reasons :  — 

The  dirt-bands  are  seen  simply  because  they  send  less 
light  to  the  eye  than  the  cleaner  portions  of  the  glacier 
which  lie  between  them ;  two  surfaces,  differently  illumi- 
nated, are  presented  to  the  eye,  and  it  is  found  that  this 
difference  is  more  observable  when  the  light  is  that  of 
evening  than  when  it  is  that  of  noon. 

It  is  only  within  certain  limits  that  the  eye  is  able  to 
perceive  differences  of  intensity  in  different  lights ;  be- 
yond a  certain  intensity,  if  I  may  use  the  expression,  light 
ceases  to  be  light,  and  becomes  mere  pain.  The  naked 
eye  can  detect  no  difference  in  brightness  between  the  elec- 


46  BANDS   SEEN  BEST   BY  TWILIGHT.  [1857. 

trie  light  and  the  lime  light,  although,  when  we  come  to 
strict  measurement,  the  former  may  possess  many  times 
the  intensity  of  the  latter.  It  follows  from  this  that  we 
might  reduce  the  ordinary  electric  light  to  a  fraction  of 
its  intensity,  without  any  perceptible  change  of  brightness 
to  the  naked  eye  which  looks  at  it.  But  if  we  reduce  the 
lime  light  in  the  same  proportion  the  effect  would  be  very 
different.  This  light  lies  much  nearer  to  the  limit  at 
which  the  eye  can  appreciate  differences  of  brightness, 
and  its  reduction  might  bring  it  quite  within  this  limit, 
and  make  it  sensibly  dimmer  than  before.  Hence  we  see 
that,  when  two  sources  of  intense  light  are  presented  to 
the  eye,  by  reducing  both  the  lights  in  the  same  propor- 
tion, the  difference  between  them  may  become  more  per- 
ceptible. 

Now  the  dirt-bands  and  the  spaces  between  them  re- 
semble, in  some  measure,  the  two  lights  above  mentioned. 
By  the  full  glare  of  noon  both  are  so  strongly  illuminated 
that  the  difference  which  the  eye  perceives  is  very  small ; 
as  the  evening  advances  the  light  of  both  is  lowered  in 
the  same  proportion,  but  the  differential  effect  upon  the 
eye  is  thereby  augmented,  and  the  bands  are  consequently 
more  clearly  seen. 


qo 

On  Friday,  the  17th  of  July,  we  commenced  our  mea- 
surements. Through  the  kindness  of  Sir  Roderick  Mur- 
chison,  I  found  myself  in  the  possession  of  an  excellent 
five-inch  theodolite,  an  instrument  with  the  use  of  which 
both  my  friend  Hirst  and  myself  were  perfectly  familiar. 


1857.]  THE   CLEFT  STATION.  47 

We  worked  in  concert  for  a  few  days  to  familiarize  our 
assistant  with  the  mode  of  proceeding,  but  afterwards  it 
was  my  custom  to  simply  determine  the  position  where  a 
measurement  was  to  be  made,  and  to  leave  the  execution 
of  it  entirely  to  Mr.  Hirst  and  our  guide. 

On  the  20th  of  July  I  made  a  long  excursion  up  the 
glacier,  examining  the  moraines,  the  crevasses,  the  struc- 
ture, the  moulins,  and  the  disintegration  of  the  s'urface. 
I  was  accompanied  by  a  boy  named  Edouard  Balmat,* 
and  found  him  .so  good  an  iceman  that  I  was  induced  to 
take  him  with  me  on  the  following  day  also. 

Looking  upwards  from  the  Montanvert  to  the  left  of  the 
Aiguille  de  Charmoz,  a  singular  gap  is  observed  in  the 
rocky  mountain  wall,  in  the  centre  of  which  stands  a  de- 
tached column  of  granite.  Both  cleft  and  pillar  are 
shown  in  the  frontispiece,  to  the  right.  The  eminence  to 
the  left  of  this  gap  is  signalised  by  Professor  Forbes  as 
one  of  the  best  stations  from  which  to  view  the  Mer  de 
Glace,  and  this  point,  which  I  shall  refer  to  hereafter  as 
the  Cleft  Station,  it  was  now  my  desire  to  attain.  From 
the  Montanvert  side  a  steep  gully  leads  to  the  cleft ;  up 
this  couloir  we  proposed  to  try  the  ascent.  At  a  consid- 
erable height  above  the  Mer  de  Glace,  and  closely  hug- 
ging the  base  of  the  Aiguille  de  Charmoz,  is  the  small 
Glacier  de  Tendue,  shown  in  the  frontispiece,  and  from 
which  a  steep  slope  stretches  down  to  the  Mer  de  Glace. 
This  Tendue  is  the  most  talkative  glacier  I  have  ever 
known  ;  the  clatter  of  the  small  stones  which  fall  from  it 
is  incessant.  Huge  masses  of  granite  also  frequently  fall 
upon  the  glacier  from  the  cliffs  above  it,  and,  being  slowly 
borne  downwards  by  the  moving  ice,  are  at  length  seen 
toppling  above  the  terminal  face  of  the  glacier.  The  ice 
which  supports  them  being  gradually  melted,  they  are  at 

*  "Le  petit  Balmat"  my  host  always  called  him. 


48  ROUGH  ASCENT.  [1857. 

length  undermined,  and  sent  bounding  down  the  slope 
with  peal  and  rattle,  according  as  the  masses  among  which 
they  move  are  large  or  small.  The  space  beneath  the  gla- 
cier is  cumbered  with  blocks  thus  sent  down;  some  of 
them  of  enormous  size. 

The  danger  arising  from  this  intermittent  cannonade, 
though  in  reality  small,  has  caused  the  guides  to  swerve 
from  the  path  which  formerly  led  across  the  slope  to  the 
promontory  of  Trelaporte.  I  say  "  small,"  because,  even 
should  a  rock  choose  the  precise  moment  at  which  a  tra- 
veller is  passing  to  leap  down,  the  boulders  at  hand  are  so 
large  and  so  capable  of  bearing  a  shock  that  the  least 
presence  of  mind  would  be  sufficient  to  place  him  in  safety. 
But  presence  of  mind  is  not  to  be  calculated  on  under 
such  circumstances,  and  hence  the  guides  were  right  to 
abandon  the  path. 

Reaching  the  mouth  of  our  gully  after  a  rough  ascent, 
we  took  to  the  snow,  instead  of  climbing  the  adjacent 
rocks.  It  was  moist  and  soft,  in  fact  in  a  condition  alto- 
gether favorable  for  the  "regelation"  of  its  granules. 
As  the  foot  pressed  upon  it  the  particles  became  cemented 
together.  A  portion  of  the  pressure  was  transmitted  lat- 
erally, which  produced  attachments  beyond  the  boundary 
of  the  foot;  thus  as  the  latter  sank,  it  pressed  upon  a 
surface  which  became  continually  wider  and  more  rigid, 
and  at  length  sufficiently  strong  to  bear  the  entire  weight 
of  the  body ;  the  pressed  snow  formed  in  fact  a  virtual 
camel's  foot,  which  soon  placed  a  limit  to  the  sinking. 
It  is  this  same  principle  of  regelation  which  enables  men 
to  cross  snow  bridges  in  safety.  By  gentle  cautious  pres- 
sure the  loose  granules  of  the  substance  are  cemented 
into  a  continuous  mass,  all  sudden  shocks  which  might 
cause  the  frozen  surfaces  to  snap  asunder  being  avoided. 
In  this  way  an  arch  of  snow  fifteen  or  twenty  inches  in 


1857.]  CHAMOIS  ON  THE  MOUNTAINS.  49 

thickness  may  be  rendered  so  firm  that  a  man  will  cross 
it,  although  it  may  span  a  chasm  one  hundred  feet  in 
depth. 

As  we  ascended,  the  incline  became  very  steep,  and 
once  or  twice  we  diverged  from  the  snow  to  the  adjacent 
rocks ;  these  were  disintegrated,  and  the  slightest  dis- 
turbance was  sufficient  to  bring  them  down ;  some  fell, 
and  from  one  of  them  I  found  it  a  little  difficult  to  es- 
cape ;  for  it  grazed  my  leg,  inflicting  a  slight  wound  as  it 
passed.  Just  before  reaching  the  cleft  at  which  we  aimed, 
the  snow  for  a  short  distance  was  exceedingly  steep,  but 
we  surmounted  it ;  and  I  sat  for  a  time  beside  the  granite 
pillar,  pleased  to  find  that  I  could  permit  my  legs  to  dan- 
gle over  a  precipice  without  prejudice  to  my  head. 

While  we  remained  here  a  chamois  made  its  appear- 
ance upon  the  rocks  above  us.  Deeming  itself  too  near, 
it  climbed  higher,  and  then  turned  round  to  watch  us. 
It  was  soon  joined  by  a  second,  and  both  formed  a 
very  pretty  picture :  their  attitudes  frequently  changed, 
but  they  were  always  graceful ;  with  head  erect  and 
horns  curved  back,  a  light  limb  thrown  forward  upon  a 
ledge  of  rock,  looking  towards  us  with  wild  and  earnest 
gaze,  each  seemed  a  type  of  freedom  and  agility.  Turn- 
ing now  to  the  left,  we  attacked  the  granite  tower,  from 
which  we  purposed  to  scan  the  glacier,  and  were  soon 
upon  its*  top.  My  companion  was  greatly  pleased,  —  he 
was  "  tres-con tent "  to  have  reached  the  place,  —  he  felt 
assured  that  many  old  guides  would  have  retreated  from 
that  ugly  gully,  with  its  shifting  shingle  and  debris,  and 
his  elation  reached  its  climax  in.  the  declaration  that,  if  I 
resolved  to  ascend  Mont  Blanc  without  a  guide,  he  was 
willing  to  accompany  me. 

From  the  position  which  we  had  attained,  the  prospect 
was  exceedingly  fine,  both  of  the  glaciers  and  of  the 
mountains.  Beside  us  was  the  Aiguille  de  Charmoz, 
4 


50  SCENE  FEOM  THE   STATION.  [1857. 

piercing  with  its  spikes  of  granite  the  clear  air.  To  my 
mind  it  is  one  of  the  finest  of  the  Aiguilles,  noble  in  mass, 
with  its  summits  singularly  cleft  and  splintered.  In  some 
atmospheric  colourings  it  has  the  exact  appearance  of  a 
mountain  of  cast  copper,  and  the  manner  in  which  some 
of  its  highest  pinnacles  are  bent,  suggesting  the  idea  of 
ductility,  gives  strength  to  the  illusion  that  the  mass  is 
metallic.  At  the  opposite  side  of  the  glacier  was  the 
Aiguille  Yerte,  with  a'  cloud  poised  upon  its  point :  it  has 
long  been  the  ambition  of  climbers  to  scale  this  peak,  and 
on  this  day  it  was  attempted  by  a  young  French  count 
with  a  long  retinue  of  guides.  He  had  not  fair  play,  for 
before  we  quitted  our  position  we  heard  the  rumble  of 
thunder  upon  the  mountain,  which  indicated  the  presence 
of  a  foe  more  terrible  than  the  avalanches  themselves. 
Higher  to  the  right,  and  also  at  the  opposite  side  of  the 
glacier,  rose  the  Aiguille  du  Moine  ;  and  beyond  was  the 
basin  of  the  Tal^fre,  the  ice  cascade  issuing  from  which 
appeared,  from  our  position,  like  the  foam  of  a  waterfall. 
Then  came  the  Aiguille  de  Le'chaud,  the  Petite  Jorasse, 
the  Grande  Jorasse,  and  the  Mont  Tacul ;  all  of  which  form 
a  cradle  for  the  Glacier  de  Lechaud.  Mont  Mallet,  the 
Pe*riades,  and  the  Aiguille  Noire,  came  next,  and  then  the 
singular  obelisk  of  the  Aiguille  du  Gdant,  from  which  a 
serrated  edge  of  cliff  descends  to  the  summit  of  the  "  Col." 
Over  the  slopes  of  the  Col  du  Ge*ant  was  spread  a  cov- 
erlet of  shining  snow,  at  some  places  apparently  as  smooth 
as  polished  marble,  at  others  broken  so  as  to  form  preci- 
pices, on  the  pale  blue  faces  of  which  the  horizontal  lines 
of  bedding  were  beautifully  drawn.  As  the  eye  approaches 
the  line  which  stretches  from  the  Rognon  to  the  Aiguille 
Noire,  the  repose  of  the  neve  becomes  more  and  more  dis- 
turbed. Yast  chasms  are  formed,  which  however  are  still 
merely  indicative  of  the  trouble  in  advance.  If  the  gla- 
cier were  lifted  off,  we  should  probably  see  that  the  line 


1857.]  SERACS   OF  THE   COL  DU  GEANT.  51 

just  referred  to  would  lie  along  the  summit  of  a  steep 
gorge  ;  over  this  summit  the  glacier  is  pushed,  and  has  its 
back  periodically  broken,  thus  forming  vast  transverse 
ridges  which  follow  each  other  in  succession  down  the 
slope.  At  the  summit  these  ridges  are  often  cleft  by 
fissures  transverse  to  them,  thus  forming  detached  towers 
of  ice  of  the  most  picturesque  and  imposing  character.* 
These  towers  often  fall ;  and  while  some  are  caught  upon 
the  platforms  of  the  cascade,  others  struggle  with  the  slow 
energy  of  a  behemoth  through  the  de*bris  which  opposes 
them,  reach  the  edges  of  the  precipices  which  rise  in  suc- 
cession along  the  fall,  leap  over,  and,  amid  ice-smoke  and 
thunder-peals,  fight  their  way  downwards. 

A  great  number  of  secondary  glaciers  were  in  sight, 
hanging  on  the  steep  slopes  of  the  mountains,  and  from 
them  streams  sped  downwards,  falling  over  the  rocks,  and 
filling  the  valley  with  a  low  rich  music.  In  front  of  me, 
for  example,  was  the  Glacier  du  Moine,  and  I  could  not 
help  feeling,  as  I  looked  at  it,  that  the  arguments  drawn 
from  the  deportment  of  such  glaciers  against  the  "  sliding 
theory,"  and  which  are  still  repeated  in  works  upon  the 
Alps,  militate  just  as  strongly  against  the  "  viscous  the- 
ory." "  How,"  demands  the  antagonist  of  the  sliding 
theory,  "  can  a  secondary  glacier  exist  upon  so  steep  a 
slope  ?  why  does  it  not  slide  down  as  an  avalanche  ?  " 
"But  how,"  the  person  addressed  may  retort,  "  can  a 
mass  which  you  assume  to  be  viscous  exist  under  similar 
conditions  ?  If  it  be  viscous,  what  prevents  it  from  roll- 
ing down  ?  "  The  sliding  theory  assumes  the  lubrication 
of  the  bed  of  the  glacier,  but  on  this  cold  height  the 
quantity  melted  is  too  small  to  lubricate  the  bed,  and 

*  To  such  towers  the  name  Seracs  is  applied.  In  the  chalets  of  Savoy, 
after  the  richer  curd  has  been  precipitated  by  rennet,  a  stronger  acid  is  used 
to  throw  down  what  remains  ;  an  inferior  kind  of  cheese  called  /Seme  is  thus 
formed,  the  shape  and  colour  of  which  have  suggested  the  application  of  the 
term  to  the  cubical  masses  of  ice. 


52  GLACIER  MOTION.  [1857. 

hence  the  slow  motion  of  these  glaciers.  Thus  a  sliding- 
theory  man  might  reason,  and,  if  the  external  deportment 
of  secondary  glaciers  were  to  decide  the  question,  De 
Saussure  might  perhaps  have  the  best  of  the  argument. 

And  with  regard  to  the  current  idea,  originated  by  M. 
de  Charpentier,  and  adopted  by  Professor  Forbes,  that  if 
a  glacier  slides  it  must  slide  as  an  avalanche,  it  may  be 
simply  retorted  that,  in  part,  it  does  so  ;  but  if  it  be  as- 
serted that  an  accelerated  motion  is  the  necessary  motion 
of  an  avalanche,  the  statement  needs  qualification.  An 
avalanche  on  passing  through  a  rough  couloir  soon  attains 
an  uniform  velocity,  —  its  motion  being  accelerated  only 
up  to  the  point  when  the  sum  of  the  resistances  acting 
upon  it  is  equal  to  the  force  drawing  it  downwards. 
These  resistances  are  furnished  by  the  numberless  asperi- 
ties which  the  mass  encounters,  and  which  incessantly 
check  its  descent,  and  render  an  accumulation  of  motion 
impossible.  The  motion  of  a  man  walking  down  stairs 
may  be  on  the  whole  uniform,  but  it  is.  really  made  up  of 
an  aggregate  of  small  motions,  each  of  which  is  acceler- 
ated ;  and  it  is  easy  to  conceive  how  a  glacier  moving 
over  an  uneven  bed,  when  released  from  one  opposing 
obstacle,  will  be  checked  by  another,  and  its  motion  thus 
rendered  sensibly  uniform. 

From  the  Aiguille  du  Ge*ant  and  Les  Periades  a  glacier 
descended,  which  was  separated  by  the  promontory  of  La 
Noire  from  the  glacier  proceeding  from  the  Col  du  G£ant. 
A  small  moraine  was  formed  between  them,  which  is 
marked  a  upon  the  diagram,  Fig.  7.  The  great  mass  of  the 
glacier  descending  from  the  Col  du  G6ant  came  next,  and 
this  was  bounded  on  the  side  nearest  to  Trelaporte  by  a 
small  moraine  6,  the  origin  of  which  I  could  not  see,  its 
upper  portion  being  shut  out  by  a  mountain  promontory. 
Between  the  moraine  b  and  the  actual  side  of  the  valley  was 
another  little  glacier,  derived  from  some  of  the  lateral  tribu- 


1857.] 


MORAINES. 


53 


taries.   It  was.  however,  between  the  moraines  a  and  b  that 
the  great  mass  of  the  Glacier  du  Ge*ant  really  lay.    At  the 


Fig.  7. 

promontory  of  the  Tacul  the  lateral  moraines  of  the  gla- 
cier des  P^riades  and  of  the  Glacier  de  Lechaud  united  to 


54  TRIBUTARIES   OF   THE   MER  DE   GLACE.         [1857. 

form  the  medial  moraine  c  of  the  Mer  de  Glace.  Car- 
rying the  eye  across  the  Ldchaud,  we  had  the  moraine  d 
formed  by  the  union  of  the  lateral  moraines  of  the  Lechaud 
and  Talefre  ;  further  to  the  left  was  the  moraine  e,  which 
came  from  the  Jar  din,  and  beyond  it  was  the  second  lateral 
moraine  of  the  Talefre.  The  Mer  de  Glace  is  formed  by 
the  confluence  of  the  whole  of  the  glaciers  here  named  ; 
being  forced  at  Trelaporte  through  a  passage,  the  width  of 
which  appears  considerably  less  than  that  of  the  single 
tributary,  the  Glacier  du  Geant. 

In  the  ice  near  Trelaporte  the  blue  veins  of  the  glacier 
are  beautifully  shown ;  but  they  vary  in  distinctness  accord- 
ing to  the  manner  in  which  they  are  looked  at.  When 
regarded  obliquely  their  colour  is  not  so  pronounced  as 
when  the  vision  plunges  deeply  into  them.  The  weathered 
ice  of  the  surface  near  Trelaporte  could  be  cloven  with  great 
facility ;  I  could  with  ease  obtain  plates  of  it  a  quarter  of 
an  inch  thick,  and  possessing  two  square  feet  of  surface. 
On  the  28th  of  July  I  followed  the  veins  several  times  from 
side  to  side  across  the  Geant  portion  of  the  Mer  de  Glace ; 
starting  from  one  side,  and  walking  along  the  veins,  my 
route  was  directed  obliquely  downwards  towards  the  axis 
of  the  tributary.  At  the  axis  I  was  forced  to  turn,  in 
order  to  keep  along  the  veins,  and  now  ascended  along 
a  line  which  formed  nearly  the  same  angle  with  the  axis 
at  the  other  side.  Thus  the  veins  led  me  as  it  were 
along  the  two  sides  of  a  triangle,  the  vertex  of  which  was 
near  the  centre  of  the  glacier.  The  vertex  was,  however, 
in  reality  rounded  off,  and  the  figure  rather  resembled  a 
hyperbola,  which  tended  to  coincidence  with  its  asymp- 
totes. This  observation  corroborates  those  of  Professor 
Forbes  with  regard  to  the  position  of  the  veins,  and,  like 
him,  I  found  that  at  the  centre  the  veining,  whose  normal 
direction  would  be  transverse  to  the  glacier,  was  contorted 
and  confused. 


1857.]  WASTING  OF  ICE.  55 

Near  the  side  of  the  Glacier  du  G£ant,  above  the  pro- 
montory of  Trelaporte,  the  ice  is  rent  in  a  remarkable 
manner.  Looking  upwards  from  the  lower  portions  of  the 
glacier,  a  series  of  vertical  walls,  rising  apparently  one 
above  the  other,  face  the  observer.  I  clambered  up  among 
these  singular  terraces,  and  now  recognise,  both  from  my 
sketch  and  memory,  that  their  peculiar  forms  are  due  to 
the  same  action  as  that  which  has  given  their  shape  to  the 
"  billows  "  of  the  Mer  de  Glace.  A  series  of  profound 
crevasses  is  first  formed.  The  Glacier  du  G6ant  deviates 
14°  from  the  meridian  line,  and  hence  the  sun  shines 
nearly  down  it  during  the  middle  portion  of  each  day. 
The  backs  of  the  ridges  between  the  crevasses  are  thus 
rounded  off,  one  boundary  of  each  fissure  is»destroyed,  or 
at  least  becomes  a  mere  steep  declivity,  while  the  other 
boundary  being  shaded  from  the  sun  preserves  its  ver- 
ticality ;  and  thus  a  very  curious  series  of  precipices  is 
formed. 

Through  all  this  dislocation,  the  little  moraine  on 
which  I  have  placed  the  letter  b  in  the  sketch  maintains 
its  right  to  existence,  and  under  it  the  laminated  struc- 
ture of  this  portion  of  the  glacier  appears  to  reach  its 
most  perfect  development.  The  moraine  was  generally 
a  mere  dirt  track,  but  one  or  two  immense  blocks  of 
granite  were  perched  upon  it.  I  examined  the  ice  under- 
neath one  of  these,  being  desirous  of  seeing  whether  the 
pressure  resulting  from  its  enormous  weight  would  pro- 
duce a  veining,  but  the  result  was  not  satisfactory. 
Veins  were  certainly  to  be  seen  in  directions  different 
from  the  normal  ones,  but  whether  they  were  due  to 
the  bending  of  the  latter,  or  were  directly  owing  to  the 
pressure  of  the  block,  I  could  not  say.  The  sides  of  a 
stream  which  had  cut  a  deep  gorge  in  the  clean  ice 
of  the  Glacier  du  Geant  afforded  a  fine  opportunity  of 
observing  the  structure.  It  was  very  remarkable, — highly 


56  GROOVES   ON  THE   SURFACE.  [1857. 

significant  indeed  in  a  theoretic  point  of  view.  Two  long 
anft  remarkably  deep  blue  veins  traversed  the  bottom  of 
the  stream,  and,  bending  upwards  at  a  place  where  the 
rivulet  curved,  drew  themselves  like  a  pair  of  parallel  lines 
upon  the  clean  white  ice.  But  the  general  structure  was 
of  a  totally  different  character  ;  it  did  not  consist  of  long 
bars,  but  approximated  to  the  lenticular  form,  and  was, 
moreover,  of  a  washy  paleness,  which  scarcely  exceeded  in 
depth  of  colouring  the  whitish  ice  around. 

To  the  investigator  of  the  structure  nothing  can  be  finer 
than  the  appearance  of  the  glacier  from  one  of  the  ice 
terraces  cut  in  the  Glacier  du  Geant  by  its  passage  round 
Trelaporte.  As  far  as  the  vision  extended  the  dirt  upon 
the  surface  of  the  ice  was  arranged  in  striae.  These  striae 
were  not  always  straight  lines,  nor  were  they  unbroken 
curves.  Within  slight  limits  the  various  parts  into  which 
a  glacier  is  cut  up  by  its  crevasses  enjoy  a  kind  of  inde- 
pendent motion.  The  grooves,  for  example,  on  two  ridges 
which  have  been  separated  by  a  small  fissure,  may  one 
day  have  their  striae  perfect  continuations  of  each  other, 
but  in  a  short  time  this  identity  of  direction  may  be 
destroyed  by  a  difference  of  motion  between  the  ridges. 
Thus  it  is  that  the  grooves  upon  the  surface  above  Trela- 
porte  are  bent  hither  and  thither,  a  crack  or  seam  always 
marking  the  point  where  their  continuity  is  ruptured. 
This  bending  occurs,  however,  within  limits  sufficiently 
small  to  enable  the  striae  to  preserve  the  same  general 
direction. 

My  attention  had  often  been  attracted  this  day  by  pro- 
jecting masses  of  what  at  first  appeared  to  be  pure  white 
snow,  rising  in  seams  above  the  general  surface  of  the 
glacier.  On  examination,  however,  I  found  them  to  be 
compact  ice,  filled  with  innumerable  air-cells,  and  so 
resistant  as  to  maintain  itself  in  some  places  at  a  height  of 
four  feet  above  the  general  level.  When  amongst  the 


1857.]  SEAMS   OF  WHITE   ICE.  57 

ridges  they  appeared  discontinuous  and  confused,  being 
scattered  apparently  at  random  over  the  glacier  ;  but  when 
viewed  from  a  sufficient  distance,  the  detached  parts 
showed  themselves  to  belong  to  a  system  of  white  seams 
which  swept  quite  across  the  Glacier  du  Ge*ant,  in  a  direc- 
tion concentric  with  the  structure.  Unable  to  account  for 
these  singular  seams,  I  climbed  up  among  the  tributary 
glaciers  on  the  Rognon  side  of  the  Glacier  du  Gdant,  and 
remained  there  until  the  sun  sank  behind  the  neighbour- 
ing peaks,  and  the  fading  light  warned  me  that  it  was 
time  to  return. 


(8.) 

Early  on  the  following  day  I  was  again  upon  the  ice. 
I  first  confined  myself  to  the  right  side  of  the  Glacier  du 
Ge*ant,  and  found  that  the  veins  of  white  ice  which  I  had 
noticed  on  the  previous  day  were  exclusively  confined  to 
this  glacier,  or  to  the  space  between  the  moraines  a  and 
b  (Fig.  7),  bending  up  so  that  the  moraine  a  between 
the  Glacier  du  Ge*ant  and  the  Glacier  des  Pe'riades  was 
tangent  to  them.  At  a  good  distance  up  the  glacier  I 
encountered  a  considerable  stream  rushing  across  it 
almost  from  side  to  side.  I  followed  the  rivulet,  examin- 
ing the  sections  which  it  exposed.  At  a  certain  point 
three  other  streams  united,  and  formed  at  their  place 
of  confluence  a  small  green  lake.  From  this  a  rivulet 
rushed,  which  was  joined  by  the  stream  whose  track  I  had 
pursued,  and  at  this  place  of  junction  a  second  green  lake 
was  formed,  from  which  flowed  a  stream  equal  in  volume 
to  the  sum  of  all  the  tributaries.  It  entered  a  crevasse, 
and  took  the  bottom  of  the  fissure  for  its  bed.  Standing 
at  the  entrance  of  the  chasm,  a  low  muffled  thunder 


58  A  LAKE   SET  FREE.  [1857. 

resounding  through  the  valley  attracted  my  attention.  I 
followed  the  crevasse,  which  deepened  and  narrowed,  and, 
by  the  blue  light  of  the  ice,  could  see  the  stream  gam- 
bolling along  its  bottom,  and  flashing  as  it  jumped  o^er 
the  ledges  which  it  encountered  in  its  way.  The  fissure 
at  length  came  to  an  end :  placing  a  foot  on  each  side 
of  it,  and  withholding  the  stronger  light  from  my  eyes, 
I  looked  down  between  its  shining  walls,  and  saw  the 
stream  plunge  into  a  shaft  which  carried  it  to  the  bottom 
of  the  glacier. 

Slowly,  and  in  zigzag  fashion,  as  the  crevasses  demanded, 
I  continued  to  ascend,  sometimes  climbing  vast  humps  of 
ice  from  which  good  views  of  the  surrounding  glacier 
were  obtained ;  sometimes  hidden  in  the  hollows  between 
the  humps,  in  which  also  green  glacier  tarns  were  often 
formed,  very  lonely  and  very  beautiful. 

While  standing  beside  one  of  these,  and  watching  the 
moving  clouds  which  it  faithfully  mirrored,  I  heard  the 
sound  of  what  appeared  to  be  a  descending  avalanche,  but 
the  time  of  its  continuance  surprised  me.  Looking  through 
my  opera-glass  in  the  direction  of  the  sound,  I  saw  issuing 
from  the  end  of  a  secondary  glacier  on  the  Tacul  side  a  tor- 
rent of  what  appeared  to  me  to  be  stones  and  mud.  I 
could  see  the  stones  and  finer  debris  jumping  down  the 
declivities,  and  shaping  themselves  into  singular  cascades. 
The  noise  continued  for  a  quarter  of  an  hour,  after  which 
the  torrent  rapidly  diminished,  until,  at  length,  the  ordi- 
nary little  stream  due  to  the  melting  of  the  glacier  alone 
remained.  A  subglacial  lake  had  burst  its  boundary,  and 
carried  along  with  it  in  its  rush  downwards  the  debris 
which  it  met  with  in  its  course. 

In  some  places  I  found  the  crevasses  difficult,  the  ice 
being  split  in  a  very  singular  manner.  Vast  plates  of 
it  not  more  than  a  foot  in  thickness  were  sometimes  de- 
tached from  the  sides  of  the  crevasses,  and  stood  alone. 


1857.]  IMPRESSIVE   SCENE.  59 

I  was  now  approaching  the  base  of  the  seracs,  and  the 
glacier  around  me  still  retained  a  portion  of  the  turbu- 
lence of  the  cascade.  I  halted  at  times  amid  the  ruin  and 
confusion,  and  examined  with  my  glass  the  cascade  itself. 
It  was  a  wild  and  wonderful  scene,  suggesting  throes  of 
spasmodic  energy,  though,  in  reality,  all  its  dislocation  had 
been  slowly  and  gradually  produced.  True,  the  stratified 
blocks  which  here  and  there  cumbered  the  terraces  sug- 
gested debacles,  but  these  were  local  and  partial,  and  did 
not  affect  the  general  question.  There  is  scarcely  a  case 
of  geological  disturbance  which  could  not  be  matched  with 
its  analogue  upon  the  glaciers,  —  contortions,  faults,  fis- 
sures, joints,  and  dislocations,  —  but  in  the  case  of  the 
ice  we  can  prove  the  effects  to  be  due  to  slowly-acting 
causes  ;  how  reasonable  is  it  then  to  ascribe  to  the  opera- 
tion of  similar  causes,  which  have  had  an  incomparably 
longer  time  to  work,  many  geological  effects  which  at  first 
sight  might  suggest  sudden  convulsion  ! 

Wandering  slowly  upwards,  successive  points  of  attrac- 
tion drawing  me  almost  unconsciously  on,  I  found  myself 
as  the  day  was  declining  deep  in  the  entanglements  of  the 
ice.  A  shower  commenced,  and  a  splendid  rainbow  threw 
an  oblique  arch  across  the  glacier.  I  was  quite  alone ; 
the  scene  was  exceedingly  impressive,  and  the  possibility 
of  difficulties  on  which  I  had  not  calculated  interven- 
ing between  me  and  the  lower  glacier,  gave  a  tinge  of 
anxiety  to  my  position.  I  turned  towards  home  ;  crossed 
some  bosses  of  ice  and  rounded  others ;  I  followed  the 
tracks  of  streams  which  were  very  irregular  on  this  portion 
of  the  glacier,  bending  hither  and  thither,  rushing  through 
deep-cut  channels,  falling  in  cascades  and  expanding  here 
and  there  to  deep  green  lakes ;  they  often  plunged  into  the 
depths  of  the  ice,  flowed  under  it  with  hollow  gurgle,  and 
reappeared  at  some  distant  point.  I  threaded  my  way 
cautiously  amid  systems  of  crevasses,  scattering  with  my 


60  CHAMOUNI  RULES.  [1857. 

axe,  to  secure  a  footing,  the  rotten  ice  of  the  sharper 
crests,  which  fell  with  a  ringing  sound  into  the  chasms  at 
either  side.  Strange  subglacial  noises  were  sometimes 
heard,  as  if  caverns  existed  underneath,  into  which  blocks 
of  ice  fell  at  intervals,  transmitting  the  shock  of  their  fall 
with  a  dull  boom  to  the  surface  of  the  glacier.  By  the 
steady  surmounting  of  difficulties  one  after  another,  I  at 
length  placed  them  all  behind  me,  and  afterwards  hastened 
swiftly  along  the  glacier  to  my  mountain  home. 

On  the  30th,  incessant  rain  confined  us  to  in-door  work  : 
on  the  31st,  we  determined  the  velocity  with  which  the 
glacier  is  forced  through  the  entrance  of  the  trunk  valley 
at  Trelaporte,  and  also  the  motion  of  the  Grand  Moulin. 
We  also  determined  both  the  velocity  and  the  width  of  the 
Glacier  du  Ge'ant.  The  1st  of  August  was  spent  by  me 
at  the  cascade  of  the  Talefre,  examining  the  structure, 
crumpling,  and  scaling  off  of  the  ice.  Finding  that  the 
rules  at  Chamouni  put  an  unpleasant  limit  to  my  demands 
on  my  guide  Simond,  I  visited  the  Guide  Chef  on  the  2nd 
of  August,  and  explained  to  him  the  object  of  my  expedi- 
tion, pointing  out  the  inconvenience  which  a  rigid  appli- 
cation of  the  rules  made  for  tourists  would  impose  upon 
me.  He  had  then  the  good  sense  to  acknowledge  the 
reasonableness  of  my  remarks,  and  to  grant  me  the  liberty 
I  requested.  The  3rd  of  August  was  employed  in  deter- 
mining the  velocity  and  width  of  the  Glacier  de  Le'chaud, 
and  in  observations  on  the  lamination  of  the  glacier. 


1857.]  THE  JARDIN.  61 

' 

THE    JARDIN. 
(9.) 

ON  the  4th  of  August,  with  a  view  of  commencing  a 
series  of  observations  on  the  inclinations  of  the  Mer  de 
Glace  and  its  tributaries,  we  had  our  theodolite  transported 
to  the  Jar  din,  which,  as  is  well  known,  lies  like  an  island 
in  the  middle  of  the  Glacier  du  Talefre.  We  reached  the 
place  by  the  usual  route,  and  found  some  tourists  reposing 
on  the  soft  green  sward  which  covers  the  lower  portion,  and 
to  which,  and  the  flowers  which  spangle  it,  the  place  owes 
its  name.  Towards  the  summit  of  the  Jardin,  a  rock  jut- 
ted forward,  apparently  the  very  apex  of  the  place,  or  at 
least  hiding  by  its  prominence  everything  that  might  exist 
behind  it ;  leaving  our  guide  with  the  instrument,  we 
aimed  at  this,  and  soon  left  the  grass  and  flowers  behind 
us.  Stepping  amid  broken  fragments  of  rock,  along 
slopes  of  granite,  with  fat  felspar  crystals  which  gave  the 
boots  a  hold,  and  crossing  at  intervals  patches  of  snow, 
which  continued  still  to  challenge  the  summer  heat,  I  at 
ength  found  myself  upon  the  peak  referred  to  ;  and,  al- 
though it  was  not  the  highest,  the  unimpeded  view  which 
t  commanded  induced  me  to  get  astride  it.  The  Jardin 
was  completely  encircled  by  the  ice  of  the  glacier,  and 
;his  was  held  in  a  mountain  basin,  which  was  bounded  all 
iround  by  a  grand  and  cliffy  rim.  The  outline  of  the  dark 
brown  crags — a  deeply  serrated  and  irregular  line — was 
forcibly  drawn  against  the  blue  heaven,  and  still  more 
strongly  against  some  white  and  fleecy  clouds  which  lay 
here  and  there  behind  it ;  while  detached  spears  and  pil- 
lars of  rock,  sculptured  by  frost  and  lightning,  stood  like 
a  kind  of  defaced  statuary  along  the  ridge.  All  round 


62  A  KESERVOIR  OF  ICE.  [1857. 

the  basin  the  snow  reared  itself  like  a  buttress  against  the 
precipitous  cliffs,  being  streaked  and  fluted  by  the  descent 
of  blocks  from  the  siimmits.  This  mighty  tub  is  the  col- 
lector of  one  of  the  tributaries  of  the  Mer  de  Glace.  Ac- 
cording to  Professor  Forbes,  its  greatest  diameter  is  4,200 
yards,  and  out  of  it  the  half-formed  ice  is  squeezed  through 
a  precipitous  gorge  about  700  yards  wide,  forming  there 
the  ice  cascade  of  the  Talefre.  Bounded  on  one  side  by 
the  Grande  Jorasse,  and  on  the  other  by  Mont  Mallet,  the 
principal  tributary  of  the  Glacier  de  Ldchaud  lay  white 
and  pure  upon  the  mountain  slope.  Round  further  to  the 
right  we  had  the  vast  plateau  whence  the  Glacier  du  G^ant 
is  fed,  fenced  on  the  left  by  the  Aiguille  du  Geant  and  the 
Aiguille  Noire,  and  on  the  right  by  the  Monts  Maudits  and 
Mont  Blanc.  The  scene  was  a  truly  majestic  one.  The 
mighty  Aiguilles  piercing  the  sea  of  air,  the  soft  white 
clouds  floating  here  and  there  behind  them  ;  the  shining 
snow  with  its  striped  faults  and  precipices ;  the  deep  blue 
firmament  overhead  ;  the  peals  of  avalanches  and  the 
sound  of  water ;  —  all  conspired  to  render  the  scene  glori- 
ous, and  our  enjoyment  of  it  deep. 

A  voice  from  above  hailed  me  as  I  moved  from  my 
perch  ;  it  was  my  friend,  who  had  found  a  lodgment 
upon  the  edge  of  a  rock  which  was  quite  detached  from 
the  Jardin,  being  the  first  to  lift  its  head  in  opposition  to 
the  descending  nev£.  Making  a  de*tour  round  a  steep 
concave  slope  of  the  glacier,  I  reached  the  flat  summit  of 
the  rorck.  The  end  of  a  ridge  of  ice  abutted  against  it, 
which  was  split  .and  bent  by  the  pressure  so  as  to  form  a 
kind  of  arch.  I  cut  steps  in  the  ice,  and  ascended  until  I 
got  beneath  the  azure  roof.  Innumerable  little  rills  of 
pellucid  water  descended  from  it.  Some  came  straight 
down,  clear  for  a  time,  and  apparently  motionless,  rapidly 
tapering  at  first,  and  more  slowly  afterwards,  until,  at  the 
point  of  maximum  contraction,  they  resolved  themselves 


1857.]  MORAINES   OF  THE    TALEFRE.  63 


into  strings  of  liquid  pearls  which  pattered  against  the  ice 
floor  underneath.  Others  again,  owing  to  the  directions 
of  the  little  streamlets  of  which  they  were  constituted, 
formed  spiral  figures  of  great  beauty :  one  liquid  vein 
wound  itself  round  another,  forming  a  spiral  protuberance, 
and  owing  to  the  centrifugal  motion  thus  imparted,  the 
vein,  at  its  place  of  rupture,  scattered  itself  laterally  in 
little  liquid  spherules.*  Even  at  this  great  elevation  the 
structure  of  the  ice  was  fairly  developed,  not  with  the 
sharpness  to  be  observed  lower  down,  but  still  perfectly  de- 
ided.  Blue  bands  crossed  the  ridge  of  ice  to  which  I  have 
referred,  at  right  angles  to  the  direction  of  the  pressure. 

I  descended,  and  found  my  friend  beneath  an  over- 
hanging rock.  Immediately  afterwards  a  peal  like  that  of 
thunder  shook  the  air,  and  right  in  front  of  us  an  ava- 
lanche darted  down  the  brown  cliffs,  then  along  a  steep 
slope  of  snow  which  reared  itself  against  the  mountain 
wall,  carrying  with  it  the  debris  of  the  rocks  over  which  it 
passed,  until  it  finally  lay  a  mass  of  sullied  rubbish  at  the 
base  of  the  incline :  the  whole  surface  of  the  Taiefre  is 
thus  soiled.  Another  peal  was  heard  immediately  after- 
wards, but  the  avalanche  which  caused  it  was  hidden 
from  us  by  a  rocky  promontory.  From  this  same  pro- 
montory the  greater  portion  of  the  medial  moraine  which 
descends  the  cascade  of  the  Taiefre  is  derived,  forming  at 
first  a  gracefully  winding  curve,  and  afterwards  stretch- 
ing straight  to  the  summit  of  the  fall.  In  the  chasms  of 
the  cascade  its  boulders  are  engulfed,  but  the  lost  moraine 
is  restored  below  the  fall,  as  if  disgorged  by  the  ice  which 
had  swallowed  it.  From  the  extremity  of  the  Jardin  it- 
self a  mere  driblet  of  a  moraine  proceeds,  running  paral- 
lel to  the  former,  and  like  it  disappearing  at  the  summit 
of  the  cascade. 

*  The  recent  hydraulic  researches  of  Professor  Magnus  furnish  some 
beautiful  illustrations  of  this  action. 


64  AMONG  THE   CREVASSES.  [1857. 

We  afterwards  descended  towards  the  cascade,  but  long 
before  this  is  attained  the  most  experienced  iceman  would 
find  himself  in  difficulty.  Transverse  crevasses  are  formed, 
which  follow  each  other  so  speedily  as  to  Ieav6  between 
them  mere  narrow  ridges  of  ice,  along  which  we  moved 
cautiously,  jumping  the  adjacent  fissures,  or  getting  round 
them,  as  the  case  demanded.  As  we  approached  the  jaws 
of  the  gorge,  the  ridges  dwindled  to  mere  plates  and 
wedges,  which  being  bent  and  broken  by  the  lateral  pres- 
sure, added  to  the  confusion,  and  warned  us  not  to  ad- 

t 

vance.  The  position  was  in  some  measure  an  exciting 
one.  Our  guide  had  never  been  here  before ;  we  were  far 
from  the  beaten  track,  and  the  riven  glacier  wore  an  as- 
pect of  treacherous  hostility.  As  at  the  base  of  the  seracs, 
a  subterranean  noise  sometimes  announced  the  falling  of 
ice-blocks  into  hollows  underneath,  the  existence  of  which 
the  resonant  concussion  of  the  fallen  mass  alone  revealed. 
There  was  thus  a  dash  of  awe  mingled  with  our  thoughts  ; 
a  stirring  up  of  the  feelings  which  troubled  the  coolness 
of  the  intellect.  We  finally  swerved  to  the  right,  and  by 
a  process  the  reverse  of  straightforward  reached  the  Cou- 
vercle.  Nightfall  found  us  at  the  threshold  of  our  hotel. 


(10.) 

On  the  5th  we  were  engaged  for  some  time  in  an  impor- 
tant measurement  of  the  Tacul.  We  afterwards  ascended 
towards  the  sSracs,  and  determined  the  inclinations  of  the 
Glacier  du  G£ant  downwards.  Dense  cloud-masses  gath- 
ered round  the  points  of  the  Aiguilles,  and  the  thunder 
bellowed  at  intervals  from  the  summit  of  Mont  Blanc.  As 
we  descended  the  Mer  de  Glace,  the  valley  in  front  of  us 
was  filled  with  a  cloud  of  pitchy  darkness.  Suddenly  from 


J857]  ROUND   HAILSTONES.  65 

side  to  side  this  field  of  gloom  was  riven  by  a  bar  of  light- 
ning of  intolerable  splendour  ;  it  was  followed  by  a  peal  of 
commensurate  grandeur,  the  echoes  of  which  leaped  from 
cliff  to  cliff  long  after  the  first  sound  had  died  away.   The 
discharge  seemed  to  unlock  the  clouds  above  us,  for  they 
showered  their  liquid  spheres  down  upon  us  with  a  mo- 
mentum like  that  of  swan-shot :  all  the  way  home  we  were 
battered  by  this  pellet-like  rain.    On  the  6th,  the  rain  con- 
tinued with  scarcely  any  pause  ;  on  the  7th,  I  was  engaged 
all  day  upon  the  Glacier  du  Gdant ;  on  the  morning  of  the 
8th,  heavy  hail  had  fallen  there,  the  stones  being  perfect 
spheres  ;  the  rounded  rain-drops  had  solidified  during  their 
descent  without  sensible  change  of  form.     When  this  hail 
was  squeezed  together,  it  exactly  resembled  a  mass  of 
oolitic  limestone  which  I  had  picked  up  in  1853  near 
Blankenburg  in  the  Harz.     Mr.  Hirst  and  myself  were  en- 
gaged together  this  day  taking  the  inclinations  :  he  struck 
his  theodolite  at  the  Angle,  and  went  home  accompanied 
by  Simond,  and,  the  evening  being  extremely  serene,  I  pur- 
sued my  way  down  the  centre  of  the  glacier  towards  the 
Echelets.   The  crevasses  as  I  advanced  became  more  deep 
and  frequent,  the  ridges  of  ice  between  them  becoming 
gradually  narrower.     They  were  very  fine,  their  down- 
ward faces  being  clear  cut,  perfectly  vertical,  and  in  many 
cases  beautifully  veined.      Vast  plates  of  ice  moreover 
often  stood  out  midway  between  the  walls  of  the  chasms, 
as  if  cloven  from  the  glacier  and  afterwards  set  on  edge. 
The  place  was  certainly  one  calculated  to  test  the  skill 
and  nerve  of  an  iceman  ;  and  as  the  day  drooped,  and 
the  shadow  in  the  valley  deepened,  a  feeling  approach- 
ing to  awe  took  possession  of  me.     My  route  was  an  exag- 
gerated zigzag  ;  right  and  left  amid  the  chasms  wherever 
a  hope  of  progress  opened ;  and  here  I  made  the  experience 
which  I  have  often  repeated  since,  and  laid  to  heart  as 
regards  intellectual  work  also,  that  enormous  difficulties 
5 


66  A  DANGEROUS   LEAP.  [1857- 

may  be  overcome  when  they  are  attacked  in  earnest. 
Sometimes  I  found  myself  so  hedged  in  by  fissures  that 
escape  seemed  absolutely  impossible ;  but  close  and  resolute 
examination  so  often  revealed  a  means  of  exit,  that  I  felt 
in  all  its  force  the  brave  verity  of  the  remark  of  Mirabeau, 
that  the  word  "  impossible  "  is  a  mere  blockhead  of  a  word. 
It  finally  became  necessary  to  reach  the  shore,  but  I  found 
this  a  work  of  extreme  difficulty.  At  length,  however,  it  be- 
came pretty  evident  that,  if  I  could  cross  a  certain  crevasse, 
my  retreat  would  be  secured.  The  width  of  the  fissure 
seemed  to  be  fairly  within  jumping  distance,  and  if  I  could 
have  calculated  on  a  safe  purchase  for  my  foot,  I  should 
have  thought  little  of  the  spring ;  but  the  ice  on  the  edge 
from  which  I  was  to  leap  was  loose  and  insecure,  and  hence 
a  kind  of  nervous  thrill  shot  through  me  as  I  made  the 
bound.  The  opposite  side  was  fairly  reached,  but  an  invo- 
luntary tremor  shook  me  all  over  after  I  felt  myself  secure. 
I  reached  the  edge  of  the  glacier  without  further  serious 
difficulty,  and  soon  after  found  myself  steeped  in  the  crea- 
ture comforts  of  our  hotel. 

On  Monday,  August  10th,  I  had  the  great  pleasure  of 
being  joined  by  my  friend  Huxley  ;  and  though  the  weather 
was  very  unpromising,  we  started  together  up  the  glacier, 
he  being  desirous  to  learn  something  of  its  general  features, 
and,  if  possible,  to  reach  the  Jardiii.  We  reached  the 
Couvercle,  and  squeezed  ourselves  through  the  Egralets  ; 
but  here  the  rain  whizzed  past  us,  and  dense  fog  settled 
upon  the  cascade  of  the  Talefre,  obscuring  all  its  parts. 
We  met  Mr.  Galton,  the  African  traveller,  returning 
from  an  attempt  upon  the  Jardin ;  and  learning  that  his 
guides  had  lost  their  way  in  the  fog,  we  deemed  it  prudent 
to  return. 

The  foregoing  brief  notes  will  have  informed  the  reader 
that  at  the  period  of  Mr.  Huxley's  arrival  I  was  not  with- 
out due  training  upon  the  ice ;  I  may  also  remark,  that 


1857.]  PREPARATIONS  FOR  A   CLIMB.  67 

on  the  25th  of  July  I  reached  the  summit  of  the  Col  du 
Ge*ant,  accompanied  by  the  boy  Balmat,  and  returned  to 
the  Montanvert  on  the  same  day.  My  health  was  perfect, 
and  incessant  practice  had  taught  me  the  art  of  dealing 
with  the  difficulties  of  the  ice.  From  the  time  of  my 
arrival  at  the  Montanvert,  the  thought  of  ascending  Mont 
Blanc,  and  thus  expanding  my  knowledge  of  the  glaciers, 
had  often  occurred  to  me,  and  I  think  I  was  justified  in 
feeling  that  the  discipline  which  both  my  friend  Hirst 
and  myself  had  undergone  ought  to  enable  us  to  accom- 
plish the  journey  in  a  much  more  modest  way  than  ordi- 
nary. I  thought  a  single  guide  sufficient  for  this  purpose, 
and  I  was  strengthened  in  this  opinion  by  the  fact  that 
Simond,  who  was  a  man  of  the  strictest  prudence,  and  who 
at  first  declared  four  guides  to  be  necessary,  had  lowered 
his  demand  first  to  two,  and  was  now  evidently  willing  to 
try  the  ascent  with  us  alone. 

On  mentioning  the  thing  to  Mr.  Huxley  he  at  once  re- 
solved to  accompany  us.  On  the  llth  of  August  the 
weather  was  exceedingly  fine,  though  the  snow  which  had 
fallen  during  the  previous  days  lay  thick  upon  the  glacier. 
At  noon  we  were  all  together  at  the  Tacul,  and  the  subject 
of  attempting  Mont  Blanc  was  mooted  and  discussed.  My 
opinion  was  that  it  would  be  better  to  wait  until  the  fresh 
snow  which  loaded  the  mountain  had  disappeared ;  but  the 
weather  was  so  exquisite  that  my  friends  thought  it  best 
to  take  advantage  of  it.  We  accordingly  entered  into  an 
agreement  with  our  guide,  and  immediately  descended  to 
make  preparations  for  commencing  the  expedition  on  the 
following  morning. 


68  SCENE  FROM  THE   CHARMOZ.  [1857. 

FIRST   ASCENT   OF   MONT   BLANC,   1857. 
(11.) 

ON  Wednesday,  the  12th  of  August,  we  rose  early,  after  a 
very  brief  rest  on  my  part.  Simond  had  proposed  to  go  down 
to  Chamouni,  and  commence  the  ascent  in  the  usual  way, 
but  we  preferred  crossing  the  mountains  from  the  Montan- 
vert,  straight  to  the  Glacier  des  Bossons.  At  eight  o'clock 
we  started,  accompanied  by  two  porters  who  were  to  carry 
our  provisions  to  the  Grands  Mulets.  Slowly  and  silently 
we  climbed  the  hill-side  towards  Charmoz.  We  soon 
passed  the  limits  of  grass  and  rhododendrons,  and  reached 
the  slabs  -of  gneiss  which  overspread  the  summit  of  the 
ridge,  lying  one  upon  the  other  like  coin  upon  the  table  of 
a  money-changer.  From  the  highest  point  I  turned  to 
have  a  last  look  at  the  Mer  de  Glace  ;  and  through  a  pair 
of  very  dark  spectacles  I  could  see  with  perfect  distinct- 
ness the  looped  dirt-bands  of  the  glacier,  which  to  the 
naked  eye  are  scarcely  discernible  except  by  twilight. 
Flanking  our  track  to  the  left  rose  a  series  of  mighty 
Aiguilles  ;  —  the  Aiguille  de  Charmoz,  with  its  bent  and 
rifted  pinnacles ;  the  Aiguille  du  Grepon,  the  Aiguille  de 
Blaitiere,  the  Aiguille  du  Midi,  all  piercing  the  heavens 
with  their  sharp  pyramidal  summits.  Far  in  front  of  us 
rose  the  grand  snow-cone  of  the  D6me  du  Goute,  while, 
through  a  forest  of  dark  pines  which  gathered  like  a 
cloud  at  the  foot  of  the  mountain,  gleamed  the  white 
minarets  of  the  Glacier  des  Bossons.  Below  us  lay  the 
Valley  of  Chamouni,  beyond  which  were  the  Brevent  and 
the  chain  of  the  Aiguilles  Rouges  ;  behind  us  was  the 
granite  obelisk  of  the  Aiguille  du  Dru,  while  close  at  hand 
science  found  a  corporeal  form  in  a  pyramid  of  stones 


1857.]  PASSAGE   TO   THE  PIERRE   L'ECHELLE.  69 

used  as  a  trigonometrical  station  by  Professor  Forbes. 
Sound  is  known  to  travel  better  up  hill  than  down,  be- 
cause the  pulses  transmitted  from  a  denser  medium  to  a 
rarer  suffer  less  loss  of  intensity  than  when  the  transmis- 
sion is  in  the  opposite  direction ;  and  now  the  mellow 
voice  of  the  Arve  came  swinging  upwards  from  the  heavier 
air  of  the  valley  to  the  lighter  air  of  the  hills  in  rich  deep 
cadences. 

The  way  for  a  time  was  excessively  rough,  our  route 
being  overspread  with  the  fragments  of  peaks  which  had 
once  reared  themselves  to  our  left,  but  which  frost  and 
lightning  had  shaken  to  pieces,  and  poured  in  granite 
avalanches  down  the  mountain.  We  were  sometimes 
among  huge  angular  boulders,  and  sometimes  amid  lighter 
shingle,  which  gave  way  at  every  step,  thus  forcing  us  to 
shift  our  footing  incessantly.  Escaping  from  these,  we 
crossed  the  succession  of  secondary  glaciers  which  lie  at 
the  feet  of  the  Aiguilles,  and,  having  secured  firewood, 
found  ourselves  after  some  hours  of  hard  work  at  the 
Pierre  I'Echelle.  Here  we  were  furnished  with  leggings 
of  coarse  woollen  cloth  to  keep  out  the  snow ;  they  were 
tied  under  the  knees  and  quite  tightly  again  over  the 
insteps,  so  that  the  legs  were  effectually  protected.  We 
had  some  refreshment,  possessed  ourselves  of  the  ladder, 
and  entered  upon  the  glacier. 

The  ice  was  excessively  fissured  :  we  crossed  crevasses 
and  crept  round  slippery  ridges,  cutting  steps  in  the  ice 
wherever  climbing  was  necessary.  This  rendered  our  pro- 
gress very  slow.  Once,  with  the  intention  of  lending  a 
helping  hand,  I  stepped  forward  upon  a  block  of  granite 
which  happened  to  be  poised  like  a  rocking  stone  upon  the 
ice,  though  I  did  not  know  it ;  it  treacherously  turned 
under  me  ;  I  fell,  but  my  hands  were  in  instant  requisition, 
and  I  escaped  with  a  bruise,  from  which,  however,  the 
blood  oozed  angrily.  We  found  the  ladder  necessary,  in 


70  LADDER  LEFT   BEHIND.  [1857. 

crossing  some  of  the  chasms,  the  iron  spikes  at  its  end 
being  firmly  driven  into  the  ice  at  one  side,  while  the 
other  end  rested  on  the  opposite  side  of  the  fissure.  The 
middle  portion  of  the  glacier  was  not  difficult.  Mounds  of 
ice  rose  beside  us  right  and  left,  which  were  sometimes 
split  into  high  towers  and  gaunt-looking  pyramids,  while 
the  space  between  was  unbroken.  Twenty  minutes'  walk- 
ing brought  us  again  to  a  fissured  portion  of  the  glacier, 
and  here  our  porter  left  the  ladder  on  the  ice  behind  him. 
For  some  time  I  was  not  aware  of  this,  but  we  were  soon 
fronted  by  a  chasm  to  pass  which  we  were  in  consequence 
compelled  to  make  a  long  and  dangerous  circuit  amid 
crests  of  crumbling  ice.  This  accomplished,  we  hoped 
that  no  repetition  of  the  process  would  occur,  but  we 
speedily  came  to  a  second  fissure,  where  it  was  neces- 
sary to  step  from  a  projecting  end  of  ice  to  a  mass  of  soft 
snow  which  overhung  the  opposite  side.  Simond  could 
reach  this  snow  with  his  long-handled  axe  ;  he  beat  it 
down  to  give  it  rigidity,  but  it  was  exceedingly  tender, 
and  as  he  worked  at  it  he  continued  to  express  his  fears 
that  it  would  not  bear  us.  I  was  the  lightest  of  the 
party,  and  therefore  tested  the  passage  first ;  being  par- 
tially lifted  by  Simond  on  the  end  of  his  axe,  I  crossed  the 
fissure,  obtained  some  anchorage  at  the  other  side,  and 
helped  the  others  over.  We  afterwards  ascended  until 
another  chasm,  deeper  and  wider  than  any  we  had  hitherto 
encountered,  arrested  us.  We  walked  alongside  of  it  in 
search  of  a  snow  bridge,  which  we  at  length  found,  but  the 
keystone  of  the  arch  had  unfortunately  given  way,  leaving 
projecting  eaves  of  snow  at  both  sides,  between  which  we 
could  look  into  the  gulf,  till  the  gloom  of  its  deeper  por- 
tions cut  the  vision  short.  Both  sides  of  the  crevasse  were 
sounded,  but  no  sure  footing  was  obtained;  the  snow  was 
beaten  and  carefully  trodden  down  as  near  to  the  edge  as 
possible,  but  it  finally  broke  away  from  the  foot  and  fell 


1857.]  DIFFICULT   CREVASSES.  71 

into  the  chasm.  One  of  our  porters  was  short-legged  and 
a  bad  iceman  ;  the  other  was  a  daring  fellow,  and  he  now 
threw  the  knapsack  from  his  shoulders,  came  to  the  edge 
of  the  crevasse,  looked  into  it,  but  drew  back  again.  After 
a  pause  he  repeated  the  act,  testing  the  snow  with  his  feet 
and  staff.  I  looked  at  the  man  as  he  stood  beside  the 
chasm  manifestly  undecided  as  to  whether  he  should  take 
the  step  upon  which  his  life  would  hang,  and  thought  it 
advisable  to  put  a  stop  to  such  perilous  play.  I  accord- 
ingly interposed,  the  man  withdrew  from  the  crevasse,  and 
he  and  Simond  descended  to  fetch  the  ladder. 

While  they  were  away  Huxley  sat  down  upon  the  ice, 
with  an  expression  of  fatigue  stamped  upon  his  counte- 
nance :  the  spirit  and  the  muscles  were  evidently  at  war, 
and  the  resolute  will  mixed  itself  strangely  with  the  sense 
of  peril  and  feeling  of  exhaustion.  He  had  been  only  two 
days  with  us,  and,  though  his  strength  is  great,  he  had  had 
no  opportunity  of  hardening  himself  by  previous  exercise 
upon  the  ice  for  the  task  which  he  had  undertaken.  The 
ladder  now  arrived,  and  we  crossed  the  crevasse.  I  was 
intentionally  the  last  of  the  party,  Huxley  being  immedi- 
ately in  front  of  me.  The  determination  of  the  man  dis- 
guised his  real  condition  from  every  body  but  myself,  but 
I  saw  that  the  exhausting  journey  over  the  boulders  and 
debris  had  been  too  much  for  his  London  limbs.  Con- 
verting my  water-proof  havresack  into  a  cushion,  I  made 
him  sit  down  upon  it  at  intervals,  and  by  thus  breaking  the 
steep  ascent  into  short  stages  we  reached  the  cabin  of  the 
Grands  Mulets  together.  Here  I  spread  a  rug  on  the 
boards,  and  placing  my  bag  for  a  pillow,  he  lay  down,  and 
after  an  hour's  profound  sleep  he  rose  refreshed  and  well ; 
but  still  he  thought  it  wise  not  to  attempt  the  ascent 
farther.  Our  porters  left  us  :  a,  baton  was  stretched  across 
the  room  over  the  stove,  and  our  wet  socks  and  leggings 
were  thrown  across  it  to  dry  ;  our  boots  were  placed 


72  STAR  TWINKLING.  [1857. 

around  the  fire,  and  we  set  about  preparing  our  evening 
meal.  A  pan  was  placed  upon  the  fire,  and  filled  with 
snow,  which  in  due  time  melted  and  boiled  ;  I  ground  some 
chocolate  and  placed  it  in  the  pan,  and  afterwards  ladled 
the  beverage  into  the  vessels  we  possessed,  which  con- 
sisted of  two  earthen  dishes  and  the  metal  cases  of  our 
brandy  flasks.  After  supper  Simond  went  out  to  inspect 
the  glacier,  and  was  observed  by  Huxley,  as  twilight  fell, 
in  a  state  of  deep  contemplation  beside  a  crevasse. 

Gradually  the  stars  appeared,  but  as  yet  no  moon.  Be- 
fore lying  down  we  went  out  to  look  at  the  firmament,  and 
noticed,  what  I  suppose  has  been  observed  to  some  extent 
by  everybody,  that  the  stars  near  the  horizon  twinkled 
busily,  while  those  near  the  zenith  shone  with  a  steady 
light.  One  large  star  in  particular  excited  our  admira- 
tion ;  it  flashed  intensely,  and  changed  colour  incessantly, 
sometimes  blushing  like  a  ruby,  and  again  gleaming  like 
an  emerald.  A  determinate  colour  would  sometimes  re- 
main constant  for  a  sensible  time,  but  usually  the  flashes 
followed  each  other  in  very  quick  succession.  Three  planks 
were  now  placed  across  the  room  near  the  stove,  and 
upon  these,  with  their  rugs  folded  round  them,  Huxley 
and  Hirst  stretched  themselves,  while  I  nestled  on  the 
boards  at  the  most  distant  end  of  the  room.  We  rose  at 
eleven  o'clock,  renewed  the  fire  and  warmed  ourselves, 
after  which  we  lay  down  again.  I  at  length  observed  a 
patch  of  pale  light  upon  the  wooden  wall  of  the  cabin, 
which  had  entered  through  a  hole  in  the  end  of  the  edifice, 
and  rising  found  that  it  was  past  one  o'clock.  The  cloud- 
less moon  was  shining  over  the  wastes  of  snow,  and  the 
scene  outside  was  at  once  wild,  grand,  and  beautiful. 

Breakfast  was  soon  prepared,  though  not  without  diffi- 
culty ;  we  had  no  candles,  they  had  been  forgotten  ;  but  I 
fortunately  possessed  a  box  of  wax  matches,  of  which  Hux- 
ley took  charge,  patiently  igniting  them  in  succession,  and 


1857.1  START  FROM   THE   GRANDS  MULETS.  73 

jhus  giving  us  a  tolerably  continuous  light.  We  had  some 
lea,  which  had  been  made  at  the  Montanvert,  and  carried 
p  the  Grands  Mulets  in  a  bottle.  My  memory  of  that  tea 
Is  not  pleasant ;  it  had  been  left  a  whole  night  in  contact 
pith  its  leaves,  and  smacked  strongly  of  tannin.  The 
mow-water,  moreover,  with  which  we  diluted  it  was  not 
lure,  but  left  a  black  residuum  at  the  bottom  of  the  dishes 
In  which  the  beverage  was  served.  The  few  provisions 
teemed  necessary  being  placed  in  Simond's  knapsack,  at 
wenty  minutes  past  two  o'clock  we  scrambled  down  the 
pcks,  leaving  Huxley  behind  us. 

The  snow  was  hardened  by  the  night's  frost,  and  we 
pere  cheered  by  the  hope  of  being  able  to  accomplish  the 
[scent  with  comparatively  little  labour.     We  were  envi- 
roned by  an  atmosphere  of  perfect  purity ;   the  larger 
Jtars  hung  like  gems  above  us,  and  the  moon,  about  half 
all,  shone  with  wondrous  radiance  in  the  dark  firmament. 
|)ne  star  in  particular,  which  lay  eastward  from  the  moon, 
juddenly  made  its  appearance  above  one  of  the  Aiguilles, 
Ind   burned   there   with    unspeakable    splendour.      We 
[urned  once  towards  the  Mulets,  and  saw  Huxley's  form 
[rejected  against  the  sky  as  he  stood  upon  a  pinnacle  of 
pck ;  he  gave  us  a  last  wave  of  the  hand  and  descended, 
Mrile  we  receded  from  him  into  the  solitudes. 
;  The  evening  previous  our  guide  had  examined  the  gla- 
jier  for  some  distance,  his  progress  having  been  arrest- 
id  by  a  crevasse.      Beside  this  we  soon  halted :   it  was 
panned  at  one  place  by  a  bridge  of  snow,  which  was  of 
DO  light  a  structure  to  permit  of  Simond's  testing  it  alone  ; 
rQ  therefore  paused  while  our  guide  uncoiled  a  rope  and 
led  us  all  together.     The  moment  was  to  me  a  peculiarly 
jlemn  one.     Our  little  party  seemed   so  lonely  and  so 
mall  amid  the  silence  and  the  vastness  of  the  surrotmd- 
ig  scene.     We  were  about  to  try  our  strength  under  un- 
nown  conditions,  and  as  the  various  possibilities  of  the 


74  A  WRONG   TURN.  [1857  [ 

enterprise  crowded  on  the  imagination,  a  sense  of  respon1 
sibility  for  a  moment  oppressed  me.  But  as  I  looked  alof  j 
and' saw  the  glory  of  the  heavens,  my  heart  lightened,  anc'j 
I  remarked  cheerily  to  Hirst  that  Nature  seemed  to  smil( 
upon  our  work.  "  Yes,"  he  replied,  in  a  calm  and  ear 
nest  voice,  "  and,  God  willing,  we  shall  accomplish  it." 

A  pale  light  now  overspread  the  eastern  sky,  which  in- 
creased, as  we  ascended,  to  a  daffodil  tinge ;  this  after- 
wards heightened  to  orange,  deepening  at  one  extremity 
into  red,  and  fading  at  the  other  into  a  pure  ethereal  hue 
to  which  it  would  be  difficult  to  assign  a  special  name 
Higher  up  the  sky  was  violet,  and  this  changed  by  insen 
sible  degrees  into  the  darkling  blue  of  the  zenith,  whicl 
had  to  thank  the  light  of  moon  and  stars  alone  for  its  ex 
istence.  We  wound  steadily  for  a  time  through  valley 
of  ice,  climbed  white  and  slippery  slopes,  crossed  a  num 
ber  of  crevasses,  and  after  some  time  found  ourselves  be 
side  a  chasm  of  great  depth  and  width,  which  extendec 
right  and  left  as  far  as  we  could  see.  We  turned  to  tin 
left,  and  marched  along  its  edge  in  search  of  a  pont ;  bu 
matters  became  gradually  worse :  other  crevasses  joinec 
on  to  the  first  one,  and  the  further  we  proceeded  the  mor< 
riven  and  dislocated  the  ice  became.  At  length  w> 
reached  a  place  where  further  advance  was  impossible 
Simond  in  his  difficulty  complained  of  the  want  of  light 
and  wished  us  to  wait  for  the  advancing  day ;  I,  on  th 
contrary,  thought  that  we  had  light  enough,  and  ought  t 
make  use  of  it.  Here  the  thought  occurred  to  me  tha 
Simond,  having  been  only  once  before  to  the  top  of  th 
mountain,  might  not  be  quite  clear  about  the  route ;  th 
glacier,  however,  changes  within  certain  limits  from  yea 
to  year,  so  that  a  general  knowledge  was  all  that  could  b 
expected,  and  we  trusted  to  our  own  muscles  to  make  goo< 
any  mistake  in  the  way  of  guidance.  We  now  turned  an< 
retraced  our  steps  along  the  edges  of  chasms  where  the  ic 


357.]  SERACS  OF   THE  DOME  DU  GOTJTE.  75 

m 

ras  disintegrated  and  insecure,  and  succeeded  at  length  in 
|  nding  a  bridge  which  bore  us  across  the  crevasse.  This 
jrror  caused  us  the  loss  of  an  hour,  and  after  walking  for  this 
jime  we  could  cast  a  stone  from  the  point  we  had  attained 
3  the  place  whence  we  had  been  compelled  to  return. 

Our  way  now  lay  along  the  face  of  a  steep  incline  of 
now,  which  was  cut  by  the  fissure  we  had  just  passed,  in 

direction  parallel  to  our  route.  On  the  heights  to  our 
ight,  loose  ice-crags  seemed  to  totter,  and  we  passed  two 
racks  over  which  the  frozen  blocks  had  rushed  some  short 
ime  previously.  We  were  glad  to  get  out  of  the  range  of 
iiese  terrible  projectiles/ and  still  more  so  to  escape  the 
iicinity  of  that  ugly  crevasse.  To  be  killed  in  the  open 
jir  would  be  a  luxury,  compared  with  having  the  life 
queezed  out  of  one  in  the  horrible  gloom  of  these  chasms, 
riie  blush  of  the  coming  day  became  more  and  more  in- 
bnse ;  still  the  sun  himself  did  not  appear,  being  hidden 
h>m  us  by  the  peaks  of  the  Aiguille  du  Midi,  which  were 
U'awn  clear  and  sharp  against  the  brightening  sky.  Right 
aider  this  Aiguille  were  heaps  of  snow  smoothly  rounded 
fcd  constituting  a  portion  of  the  sources  whence  the  Gla- 
jier  du  Geant  is  fed  ;  these,  as  the  day  advanced,  bloomed 
nth  a  rosy  light.  We  reached  the  Petit  Plateau,  which 
rQ  found  covered  with  the  remains  of  ice  avalanches ; 
ibove  us  upon  the  crest  of  the  mountain  rose  three  mighty 
astions,  divided  from  each  other  by  deep  vertical  rents, 
:rith  clean  smooth  walls,  across  which  the  lines  of  annual 
tedding  were  drawn  like  courses  of  masonry.  From  these, 
rhich  incessantly  renew  themselves,  and  from  the  loose 
ind  broken  ice-crags  near  them,  the  boulders  amid  which 
re  now  threaded  our  way  had  been  discharged.  When 
;:iey  fall,  their  descent  must  be  sublime. 
i  The  snow  had  been  gradually  getting  deeper,  and  the 

scent  more  wearisome,  but  superadded  to  this  at  the  Petit 
s'lateau  was  the  uncertainty  of  the  footing  between  the 


76  THE  LOST   GUIDES.  [1857 

blocks  of  ice.     In  many  places  the  space  was  merely  co\ 
ered  by  a  thin  crust,  which,  when  trod  upon,  instantl 
yielded,  and  we  sank  with  a  shock  sometimes  to  the  hips 
Our  way  next  lay  up  a  steep  incline  to  the  Grand  Plateau 
the  depth  and  tenderness  of  the  snow  augmenting  as  w 
ascended.     We  had  not  yet  seen  the  sun,  but,  as  we  al 
tained  the  brow  which  forms  the  entrance  to  the  Grain 
Plateau,  he  hung  his  disk  upon  a  spike  of  rock  to  ou 
left,  and,  surrounded  by  a  glory  of  interference  spectra  c 
the  most  gorgeous  colors,  blazed  down  upon  us.     On  th 
Grand  Plateau  we  halted  and  had  our  frugal  refreshment 
At  some  distance  to  our  left  was  the  crevasse  into  whic: 
Dr.  Hamel's  three  guides  were  precipitated  by  an  av 
lanche  in  1820 ;  they  are  still  entombed  in  the  ice,  an 
some  future  explorer  may  perhaps  see  them  disgorg 
lower  down,  fresh  and  undecayed.     They  can  hardly  reaci 
the  surface  until  they  pass  the  snow-line  of  the  glacier,  fo 
above  this  line  the  quantity  of  snow  that  annually  fa 
being  in  excess  of  the  quantity  melted,  the  tendency  wou 
be  to  make  the  ice-covering  above  them  thicker.     But  i 
is  also  possible  that  the  waste  of  the  ice  underneath  m 
have  brought  the  bodies  to  the  bed  of  the  glacier,  whe 
their  very  bones  may  have  been  ground  to  mud  by 
agency  which  the  hardest  rocks  cannot  withstand. 

As  the  sun  poured  his  light  upon  the  Plateau  the  lit 
snow-facets  sparkled  brilliantly,  sometimes  with  a  pu 
white  light,  and  at  others  with  prismatic  colours.  Cor 
trasted  with  the  white  spaces  above  and  around  us  wer 
the  dark  mountains  on  the  opposite  side  of  the  valley  c 
Chamouni,  around  which  fantastic  masses  of  cloud  wer 
beginning  to  build  themselves.  Mont  Buet,  with  its  con 
of  snow,  looked  small,  and  the  Brevent  altogether  mean 
the  limestone  bastions  of  the  Fys,  however,  still  pre 
sented  a  front  of  gloom  and  grandeur.  We  traverse* 
the  Grand  Plateau,  and  at  length  reached  the  base  of  ai 


7.]  THE   GUIDE   TIRED.  77 

tremely  steep  incline  which  stretched  upwards  towards 
e  Corridor.  Here,  as  if  produced  by  a  fault,  consequent 
pon  the  sinking  of  the  ice  in  front,  rose  a  vertical  preci- 
ice,  from  the  coping  of  which  vast  stalactites  of  ice  de- 
ended.  Previous  to  reaching  this  place  I  had  noticed  a 
aggard  expression  upon  the  countenance  of  our  guide, 
hich  was  now  intensified  by  the  prospect  of  the  ascent 
efore  him.  Hitherto  he  had  always  been  in  front,  which 
ras  certainly  the  most  fatiguing  position.  I  felt  that  I 
mst  now  take  the  lead,  so  I  spoke  cheerily  to  the  man 
nd  placed  him  behind  me.  Marking  a  number  of  points 
pon  the  slope  as  resting-places,  I  went  swiftly  from  one 
3  the  other.  The  surface  of  the  snow  had  been  partially 
lelted  by  the  sun  and  then  refrozen,  thus  forming  a  super- 
cial  crust,  which  bore  the  weight  up  to  a  certain  point 
nd  then  suddenly  gave  way,  permitting  the  leg  to  sink 
above  the  knee.  The  shock  consequent  on  this,  and 
subsequent  effort  necessary  to  extricate  the  leg,  were 
xtremely  fatiguing.  My  motion  was  complained  of  as 
)o  quick,  and  my  tracks  as  imperfect ;  I  moderated  the 
)rmer,  and,  to  render  my  footholes  broad  and  sure,  I 
tamped  upon  the  frozen  crust,  and  twisted  my  legs  in  the 
)ft  mass  underneath,  —  a  terribly  exhausting  process.  I 
.ins  led  the  way  to  the  base  of  the  Rochers  Rouges,  up  to 
rhich  the  fault  already  referred  to  had  prolonged  itself  as 
i  crevasse,  which  was  roofed  at  one  place  by  a  most  dan- 
gerous-looking snow-bridge.  Simond  came  to  the  front ; 
|  drew  his  attention  to  the  state  of  the  snow,  and  proposed 
jlimbing  the  Rochers  Rouges  ;  but,  with  a  promptness  un- 
sual with  him,  he  replied  that  this  was  impossible  ;  the 
ridge  was  our  only  means  of  passing,  and  we  must  try  it. 
Ve  grasped  our  ropes,  and  dug  our  feet  firmly  into  the 
ftiow  to  check  the  man's  descent  if  the  pont  gave  way,  but 
to  our  astonishment  it  bore  him,  and  bore  us  safely  after 
im.  The  slope  which  we  had  now  to  ascend  had  the  snow 


78  A  PERILOUS   SLOPE.  [185s 

swept  from  its  surface,  and  was  therefore  firm  ice.  It  w; 
most  dangerously  steep,  and,  its  termination  being  the  frel 
ted  coping  of  the  precipice  to  which  I  have  referred,  if  \\ 
slid  downwards  we  should  shoot  over  this  and  be  dashe 
to  pieces  upon  the  ice  below.*  Simond,  who  had  come  1 
the  front  to  cross  the  crevasse,  was  now  engaged  in  cuttin 
steps,  which  he  made  deep  and  large,  so  that  they  migl 
serve  us  on  our  return.  But  the  listless  strokes  of  h 
axe  proclaimed  his  exhaustion  ;  so  I  took  the  implemei 
out  of  his  hands  and  changed  places  with  him.  Step  aft( 
step  was  hewn,  but  the  top  of  the  Corridor  appeared  ev( 
to  recede  from  us.  Hirst  was  behind  unoccupied,  an 
could  thus  turn  his  thoughts  to  the  peril  of  our  position 
h&felt  the  angle  on  which  we  hung,  and  saw  the  edge  < 
the  precipice,  to  which  less  than  a  quarter  of  a  minute 
slide  would  carry  us,  and  for  the  first  time  during  tl 
journey  he  grew  giddy.  A  cigar  which  he  lighted  for  tl 
purpose  tranquillized  him. 

I  hewed  sixty  steps  upon  this  slope,  and  each  step  ha 
cost  a  minute,  by  Hirst's  watch.  The  Mur  de  la  Cote  ws 
still  before  us,  and  on  this  the  guide-books  informed  us  t\* 
or  three  hundred  steps  were  sometimes  found  necessar; 
If  sixty  steps  cost  an  hour,  what  would  be  the  cost  of  t\* 
hundred  ?  The  question  was  disheartening  in  the  e: 
treme,  for  the  time  at  which  we  had  calculated  on  read 
ing  the  summit  was  already  passed,  while  the  chief  difl 
culties  remained  unconquered.  Having  hewn  our  wa 
along  the  harder  ice  we  reached  snow.  I  again  resorte 
to  stamping  to  secure  a  footing,  and  while  thus  engage 
became,  for  the  first  time,  aware  of  the  drain  of  fore 
to  which  I  was  subjecting  myself.  The  thought  of  bein 

*  Those  acquainted  with  the  mountain  will  at  once  recognise  the  gra1 
error  here  committed.  In  fact,  on  starting  from  the  Grands  Mulcts  we  hi 
crossed  the  glacier  too  far,  and  throughout  were  much  too  close  to  the  Don 
du  Goute. 


57.]  WILL  AND  MUSCLE.  79 

isolutely  exhausted  had  never  occurred  to  me,  and  from 
•st  to  last  I  had  taken  no  care  to  husband  my  strength.  I 
ways  calculated  that  the  will  would  serve  me  even  should 
ie  muscles  fail,  but  I  now  found  that  mechanical  laws  rule 
an  in  the  long  run ;  that  no  effort  of  will,  no  power  of 
drit,  can  draw  beyond  a  certain  limit  upon  muscular  force, 
he  soul,  it  is  true,  can  stir  the  body  to  action,  but  its 
nction  is  to  excite  and  apply  force,  and  not  to  create  it. 
While  stamping  forward  through  the  frozen  crust  I  was 
mpelled  to  pause  at  short  intervals  ;  then  would  set  out 
ain  apparently  fresh,  to  find,  however,  in  a  few  minutes, 
lat  my  strength  was  gone,  and  that  I  required  to  rest 
ice  more.  In  this  way  I  gained  the  summit  of  the  Cor- 
dor,  when  Hirst  came  to  the  front,  and  I  felt  some  relief 
i  stepping  slowly  after  him,  making  use  of  the  holes  into 
hich  his  feet  had  sunk.  He  thus  led  the  way  to  the  base 
*  the  Mur  de  la  Cote,  the  thought  of  which  had  so  long 
ist  a  gloom  upon  us  ;  here  we  left  our  rope  ^behind  us, 
nd  while  pausing  I  asked  Simond  whether  he  did  not  feel 
desire  to  go  to  the  summit.  "  Bien  sur"  was  his  reply, 
mais  /"  Our  guide's  mind  was  so  constituted  that  the 
mais  "  seemed  essential  to  its  peace.  I  stretched  my 
and  towards  him,  and  said,  "  Simond,  we  must  do  it." 
ne  thing  alone  I  felt  could  defeat  us :  the  usual  time  of 
ie  ascent  had  been  more  than  doubled,  the  day  was 
Iready  far  spent,  and  if  the  ascent  would  throw  our  sub- 
iquent  descent  into  night  it  could  not  be  contemplated. 
We  now  faced  the  Mur,  which  was  by  no  means  so  bad 
3  we  had  expected.  Driving  the  iron  claws  of  our  boots 
ito  the  scars  made  by  the  axe,  and  the  spikes  of  our 
atons  into  the  slope  above  our  feet,  we  ascended  steadily 
ntil  the  summit  was  attained,  and  the  top  of  the  moun- 
lin  rose  clearly  above  us.  We  congratulated  ourselves 
pon  this  ;  but  Simond,  probably  fearing  that  our  joy 
light  become  too  full,  remarked,  "  Mais  Ie  sommet  est  en- 


80  A  DOZE   ON  THE   CALOTTE.  [ISgl 

core  bien  loin  !  "  It  was,  alas  !  too  true.  The  snow  b 
came  soft  again,  and  our  weary  limbs  sank  in  it  as  befor 
Our  guide  went  on  in  front,  audibly  muttering  his  doub 
as  to  our  ability  to  reach  the  top,  and  at  length  he  thre 
himself  upon  the  snow,  and  exclaimed,  "  llfaut  le  reno\ 
cer  !  "  Hirst  now  undertook  the  task  of  rekindling  tl 
guide's  enthusiasm,  after  which  Simond  rose,  exclaimin: 
u  Ah  !  comme  $a  me  fait  mal  aux  genoux"  and  went  fo 
ward.  Two  rocks  break  through  the  snow  between  tl 
summit  of  the  Mur  and  the  top  of  the  mountain  ;  the  fir 
is  called  the  Petits  Mulcts,  and  the  highest  the  Dernie 
Rochers.  At  the  former  of  these  we  paused  to  rest,  an 
finished  our  scanty  store  of  wine  and  provisions.  We  ha 
not  a  bit  of  bread  nor  a  drop  of  wine  left ;  our  brand 
flasks  were  also  nearly  exhausted,  and  thus  we  had  to  coi 
template  a  journey  to  the  summit,  and  the  subsequei 
descent  to  the  Grands  Mulcts,  without  the  slightest  pro 
pect  of  physical  refreshment.  The  almost  total  loss  < 
two  nights'  sleep,  with  two  days'  toil  superadded,  mac 
me  long  for  a  few  minutes'  doze,  so  I  stretched  myse 
upon  a  composite  couch  of  snow  and  granite,  and  inun< 
diately  fell  asleep.  My  friend,  however,  soon  aroused  m< 
"  You  quite  frighten  me,"  he  said  ;  "  I  have  listened  ft 
some  minutes,  and  have  not  heard  you  breathe  once." 
had,  in  reality,  been  taking  deep  draughts  of  the  mountai 
air,  but  so  silently  as  not  to  be  heard. 

I  now  filled  our  empty  wine-bottle  with  snow  and  place 
it  in  the  sunshine,  that  we  might  have  a  little  water  o 
our  return.  We  then  rose  ;  it  was  half-past  two  o'clock 
we  had  been  upwards  of  twelve  hours  climbing,  and  I  ca 
culated  that,  whether  we  reached  the  summit  or  not,  ^ 
could  at  all  events  work  towards  it  for  another  hour.  T 
the  sense  of  fatigue  previously  experienced,  a  new  ph< 
nomcnon  was  now  added,  —  the  beating  of  the  heart.  W 
were  incessantly  pulled  up  by  this,  which  sometimes  b< 


857.]  THE   SUMMIT  ATTAINED.  81 


82  CLOUDS  FROM  THE   SUMMIT.  [1857. 

Talefre  with  its  surrounding  peaks,  the  Grand  Jorasse. 
Mont  Mallet,  and  the  Aiguille  du  Ge*ant,  with  our  own 
familiar  glaciers,  were  all  below  us.  And  as  our  eye 
ranged  over  the  broad  shoulders  of  the  mountain,  over 
ice  hills  and  valleys,  plateaux  and  far-stretching  slopes  o: 
snow,  the  conception  of  its  magnitude  grew  upon  us,  anc 
impressed  us  more  and  more. 

The  clouds  were  very  grand, — grander  indeed  than 
anything  I  had  ever  before  seen.  Some  of  them  seemec 
to  hold  thunder  in  their  breasts,'  they  were  so  dense  and 
dark  ;  others,  with  their  faces  turned  sunward,  shone  with 
the  dazzling  whiteness  of  the  mountain  snow  ;  while  others 
again  built  themselves  into  forms  resembling  gigantic  elm 
trees,  loaded  with  foliage.  Towards  the  horizon  the  lux- 
ury of  colour  added  itself  to  the  magnificent  alternation  o: 
light  and  shade.  Clear  spaces  of  amber  and  ethereal  green 
embraced  the  red  and  purple  cumuli,  and  seemed  to  form 
the  cradle  in  which  they  swung.  Closer  at  hand,  squally 
mists,  suddenly  engendered,  were  driven  hither  and  thithei 
by  local  winds  ;  while  the  clouds  at  a  distance  lay  "  like 
angels  sleeping  on  the  wing,"  with  scarcely  visible  motion. 
Mingling ,  with  the  clouds,  and  sometimes  rising  above 
them,  were  the  highest  mountain  heads,  and  as  our  eyes 
wandered  fronvpeak  to  peak,  onwards  to  the  remote  hori-i 
zon,  space  itself  seemed  more  vast  from  the  manner  in 
which  the  objects  which  it  held  were  distributed. 

I  wished  to  repeat  the1  remarkable  experiment  of  De 
Saussure  upon  sound,  and  for  this  purpose  had  requested 
Simond  to  bring  a  pistol  from  Chamouni ;  but  in  the  mul- 
titude of  his  cares  he  forgot  it,  and  in  lieu  of  it  my  host  ai 
the  Montanvert  had  placed  in  two  tin  tubes,  of  the  same 
size  and  shape,  the  same  amount  of  gunpowder,  securely 
closing  the  tubes  afterwards,  and  furnishing  each  of  them 
with  a  small  lateral  aperture.  We  now  planted  one  oi 
them  upon  the  snow,  and  bringing  a  strip  of  amadou  into 


1857.]  INTENSITY  OF   SOUND.  83 

communication  with  the  touchhole,  ignited  its  most  dis- 
tant end :  it  failed  ;  we  tried  again,  and  were  successful, 
the  explosion  tearing  asunder  the  little  case  which  con- 
tained the  powder.  The  sound  was  certainly  not  so  great 
as  I  should  have  expected  from  an  equal  quantity  of  pow- 
der at  the  sea  level.* 

The  snow  upon  the  summit  was  indurated,  but  of  an 
exceedingly  fine  grain,  and  the  beautiful  effect  already 
referred  to  as  noticed  upon  the  Stelvio  was  strikingly 
manifest.  The  hole  made  by  driving  the  baton  into  the 
snow  was  filled  with  a  delicate  blue  light ;  and,  by  manage- 
ment, its  complementary  pinky  yellow  could  also  be  pro- 
duced. Even  the  iron  spike  at  the  end  of  the  baton  made 
a  hole  sufficiently  deep  to  exhibit  the  blue  colour,  which 
certainly  depends  on  the  size  and  arrangement  of  the  snow 
crystals.  The  firmament  above  us  was  without  a  cloud, 
and  of  a  darkness  almost  equal  to  that  which  surrounded 
the  moon  at  2  A.  M.  Still,  though  the  sun  was  shining, 
a  breeze,  whose  tooth  had  been  sharpened  by  its  passage 
over  the  snow-fields,  searched  us  through  and  through. 
The  day  was  also  waning,  and,  urged  by  the  warnings  of 
our  ever  prudent  guide,  we  at  length  began  the  descent. 

Gravity  was  now  in  our  favour,  but  gravity  could  not 
entirely  spare  our  wearied  limbs,  and  where  we  sank  in 
the  snow  we  found  our  downward  progress  very  trying.  I 
suffered  from  thirst,  but  after  we  had  divided  the  liquefied 
snow  at  the  Petits  Mulcts  amongst  us  we  had  nothing  to 
drink.  I  crammed  the  clean  snow  into  my  mouth,  but  the 
process  of  melting  was  slow  and  tantalizing  to  a  parched 
throat,  while  the  chill  was  painful  to  the  teeth.  We 

*  I  fired  the  second  case  in  a  field  in  Hampshire,  and,  as  far  as  my  memory 
enabled  me  to  make  the  comparison,  found  its  sound  considerably  denser,  if  I 
may  use  the  expression.  In  1859  I  had  a  pistol  fired  at  the  summit  of  Mont 
Blanc :  its  sound  was  sensibly  feebler  and  shorter  than  in  the  valley ;  it  resem- 
bled somewhat  the  discharge  of  a  cork  from  a  champagne  bottle,  though  much 
louder,  but  it  could  not  be  at  all  compared  to  the  sound  of  a  common  cracker. 


84  AN  UNEXPECTED   GLISSADE.  [1857. 

marched  along  the  Corridor,  and  crossed  cautiously  the 
perilous  slope  on  which  we  had  cut  steps  in  the  morning, 
breathing  more  freely  after  we  had  cleared  the  ice-preci- 
pice before  described.  Along  the  base  of  this  precipice 
we  now  wound,  diverging  from  our  morning's  track,  in 
order  to  get  surer  footing  in  the  snow  ;  it  was  like  flour, 
and  while  descending  to  the  Grand  Plateau  we  sometimes 
sank  in  it  nearly  to  the  waist.  When  I  endeavoured  to 
squeeze  it,  so  as  to  fill  my  flask,  it  at  first  refused  to  cling 
together,  behaving  like  so  much  salt;  the  heat  of  the 
hand,  however,  soon  rendered  it  a  little  moist,  and  capa- 
ble of  being  pressed  into  compact  masses.  The  sun  met 
us.  here  with  extraordinary  power ;  the  heat  relaxed  my 
muscles,  but  when  fairly  immersed  in  the  shadow  of  the 
Dome  du  Goute*,  the  coolness  restored  my  strength,  which 
augmented  as  the  evening  advanced.  Simond  insisted  on 
the  necessity  of  haste,  to  save  us  from  the  perils  of  dark- 
ness. "  On  pent  perir  "  was  his  repeated  admonition,  and 
he  was  quite  right.  We  reached  the  region  of  ponts, 
more  weary,  but,  in  compensation,  more  callous,  than  we 
had  been  in  the  morning,  and  moved  over  the  soft  snow 
of  the  bridges  as  if  we  had  been  walking  upon  eggs.  The 
valley  of  Chamouni  was  filled  with  brown-red  clouds, 
which  crept  towards  us  up  the  mountain  ;  the  air  around 
and  above  us  was,  however,  clear,  and  the  chastened  light 
told  us  that  day  was  departing.  Once  as  we  hung  upon 
a  steep  slope,  where  the  snow  was  exceedingly  soft,  Hirst 
omitted  to  make  his  footing  sure ;  the  soft  mass  gave  way, 
and  he  fell,  uttering  a  startled  shout  as  he  went  down  the 
declivity.  I  was  attached  to  him,  and,  fixing  my  feet 
suddenly  in  the  snow,  endeavoured  to  check  his  fall,  but 
I  seemed  a  mere  feather  in  opposition  to  the  force  with 
which  he  descended.*  I  fell,  and  went  down  after  him  ; 
and  we  carried  quite  an  avalanche  of  snow  along  with  us, 

*  I  believe  that  I  could  stop  him  now  (1860). 


1857.]  BLIND  AMID    THE    CREVASSES.  85 

in  which  we  were  almost  completely  hidden  at  the  bottom 
of  the  slope.  All  further  dangers,  however,  were  soon 
past,  and  we  went  at  a  headlong  speed  to  the  base  of  the 
Grands  Mulets,  the  sound  of  our  batons  against  the  rocks 
calling  Huxley  forth.  A  position  more  desolate  than  his 
had  been  can  hardly  be  imagined.  For  seventeen  hours 
he  had  been  there.  He  had  expected  us  at  two  o'clock  in 
the  afternoon  ;  the  hours  came  and  passed,  and  till  seven 
in  the  evening  he  had  looked  for  us.  "  To  the  end  of  my 
life,"  he  said,  "  I  shall  never  forget  the  sound  of  those 
batons."  It  was  his  turn  now  to  nurse  me,  which  he  did, 
repaying  my  previous  care  of  him  with  high  interest.  We 
were  all  soon  stretched,  and,  in  spite  of  cold  and  hard 
boards,  I  slept  at  intervals  ;  but  the  night,  on  the  whole, 
was  a  weary  one,  and  we  rose  next  morning  with  muscles 
more  tired  than  when  we  lay  down. 

Friday,  14£/i  August.  —  Hirst  was  almost  blind  this 
morning :  and  our  guide's  eyes  were  also  greatly  inflamed. 
We  gathered  our  things  together,  and  bade  the  Grands 
Mulets  farewell.  It  had  frozen  hard  during  the  night, 
and  this,  on  the  steeper  slopes,  rendered  the  footing  very 
insecure.  Simond,  moreover,  appeared  to  be  a  little  be- 
wildered, and  I  sometimes  preceded  him  in  cutting  the 
steps,  while  Hirst  moved  among  the  crevasses  like  a  blind 
man  ;  one  of  us  keeping  near  him,  so  that  he  might  feel  for 
the  actual  places  where  our  feet  had  rested,  and  place  his 
own  in  the  same  position.  It  cost  us  three  hours  to  cross 
from  the  Grands  Mulets  to  the  Pierre  1'Echelle,  where  we 
discarded  our  leggings,  had  a  mouthful  of  food,  and  a  brief 
rest.  Once  upon  the  safe  earth  Simond' s  powers  seemed  to 
be  restored,  and  he  led  us  swiftly  downwards  to  the  little 
auberge  beside  the  Cascade  du  Tard,  where  we  had  some 
excellent  lemonade,  equally  choice  cognac,  fresh  straw- 
berries and  cream.  How  sweet  they  were,  and  how  beau- 
tiful we  thought  the  peasant  girl  who  served  them  !  Our 


86  HAPPY  EVENINGS.  [1857. 

guide  kept  a  little  hotel,  at  which  we  halted,  and  found  it 
clean  and  comfortable.  We  were,  in  fact,  totally  unfit 
to  go  elsewhere.  My  coat  was  torn,  holes  were  kicked 
through  my  boots,  and  I  was  altogether  ragged  and  shab- 
by. A  warm  bath  before  dinner  refreshed  all  mightily. 
Dense  clouds  now  lowered  upon  Mont  Blanc,  and  we  had 
not  been  an  hour  at  Chamouni  when  the  breaking  up  of 
the  weather  was  announced  by  a  thunder-peal.  We  had 
accomplished  our  journey  just  in  time. 


(12-). 

After  our  return  we  spent  every  available  hour  upon  the 
ice,  working  at  questions  which  shall  be  treated  under 
their  proper  heads,  each  day's  work  being  wound  up  by 
an  evening  of  perfect  enjoyment.  Roast  mutton  and  fried 
potatoes  were  our  incessant  fare,  for  which,  after  a  little 
longing  for  a  change  at  first,  we  contracted  a  final  and 
permanent  love.  As  the  year  advanced,  moreover,  and 
the  grass  sprouted  with  augmented  vigour  on  the  slopes 
of  the  Montanvert,  the  mutton,  as  predicted  by  our  host, 
became  more  tender  and  juicy.  We  had  also  some  capital 
Sallenches  beer,  cold  as  the  glacier  water,  but  effervescent 
as  champagne.  Such  were  our  food  and  drink.  After  din- 
ner we  gathered  round  the  pine-fire,  and  I  can  hardly  think 
it  possible  for  three  men  to  be  more  happy  than  we  then 
were.  It  was  not  the  goodness  of  the  conversation,  nor  any 
high  intellectual  element,  which  gave  the  charm  to  our 
gatherings  ;  the  gladness  grew  naturally  out  of  our  own 
perfect  health,  and  out  of  the  circumstances  of  our  position. 
Every  fibre  seemed  a  repository  of  latent  joy,  which  the 
slightest  stimulus  sufficed  to  bring  into  conscious  action. 

On  the  17th,  I  penetrated  with  Simond  through  thick 
gloom  to  the  Tacul ;  on  the  18th,  we  set  stakes  at  the  same 


1857.]  A  GLACIER  "BLOWER."  87 

place  :  on  the  same  day,  while  crossing  the  medial  moraine 
of  the  Talefre,  a  little  below  the  cascade,  a  singular  noise 
attracted  my  attention ;  it  seemed  at  first  as  if  a  snake 
were  hissing  about  my  feet.  On  changing  my  position  the 
sound  suddenly  ceased,  but  it  soon  recommenced.  There 
was  some  snow  upon  the  glacier,  which  I  removed,  and 
placed  my  ear  close  to  the  ice,  but  it  was  difficult 
to  fix  on  the  precise  spot  from  which  the  sound  issued. 
I  cut  away  the  disintegrated  portion  of  the  surface,  and 
at  length  discovered  a  minute  crack,  from  which  a 
stream  of  air  issued,  which  I  could  feel  as  a  cold  blast 
against  my  hand.  While  cutting  away  the  surface  fur- 
ther, I  stopped  the  little  "  blower."  A  marmot  screamed 
near  me,  and  while  I  paused  to  look  at  the  creature 
scampering  up  the  crags,  the  sound  commenced  again, 
changing  its  note  variously,  —  hissing  like  a  snake,  sing- 
ing like  a  kettle,  and  sometimes  chirruping  intermittently 
like  a  bird.  On  passing  my  fingers  to  and  fro  over 
the  crack,  I  obtained  a  succession  of  audible  puffs ;  the 
current  was  sufficiently  strong  to  blow  away  the  corner  of 
my  gauze  veil  when  held  over  the  fissure.  Still  the  crack 
was  not  wide  enough  to  permit  of  the  entrance  of  my 
finger  nail ;  and  to  issue  with  such  force  from  so  minute  a 
rent  the  air  must  have  been  under  considerable  pressure. 
The  origin  of  the  blower  was  in  all  probability  the  fol- 
lowing. When  the  ice  is  recompacted  after  having  de- 
scended a  cascade,  it  is  next  to  certain  that  chambers  of 
air  will  be  here  and  there  enclosed,  which,  being  power- 
fully squeezed  afterwards,  will  issue  in  the  manner  de- 
scribed whenever  a  crack  in  the  ice  furnishes  it  with  a 
means  of  escape.  In  my  experiments  on  flowing  mud,  for 
example,  the  air  entrapped  in  the  mass  while  descending 
from  the  sluice  into  the  trough,  bursts  in  bubbles  from  the 
surface  at  a  short  distance  downwards. 

I  afterwards  examined  the  Talefre  cascade  from  summit 


88  A  DIFFICULT  LINE.  [1857. 

to  base,  with  reference  to  the  structure,  until  at  the  close 
of  the  day  thickening  clouds  warned  me  off.  I  went  down 
the  glacier  at  a  trot,  guided  by  the  boulders  capped  with 
little  cairns  which  marked  the  route.  The  track  which  I 
had  pursued  for  the  last  five  weeks  amid  the  crevasses  near 
1' Angle  was  this  day  barely  passable.  The  glacier  had 
changed,  my  work  was  drawing  to  a  close,  and,  as  I  looked 
at  the  objects  which  had  now  become  so  familiar  to  me, 
I  felt  that,  though  not  viscous,  the  ice  did  not  lack  the 
quality  of  "  adhesiveness,"  and  I  felt  a  little  sad  at  the 
thought  of  bidding  it  so  soon  farewell. 

At  some  distance  below  the  Montanvert  the  Mer  de 
Glace  is  riven  from  side  to  side  by  transverse  crevasses.: 
these  fissures  indicate  that  the  glacier  where  they  occur  is 
in  a  state  of  longitudinal  strain  which  produces  transverse 
fracture.  I  wished  to  ascertain  the  amount  of  stretch- 
ing which  the  glacier  here  demanded,  and  which  the 
ice  was  not  able  to  give;  and  for  this  purpose  desired  to 
compare  the  velocity  of  a  line  set  out  across  .the  fissured 
portion  with  that  of  a  second  line  staked  out  across  the  ice 
before  it  had  become  thus  fissured.  A  previous  inspection 
of  the  glacier  through  the  telescope  of  our  theodolite  in- 
duced us  to  fix  on  a  place  which,  though  much  riven,  still 
did  not  exclude  the  hope  of  our  being  able  to. reach  the 
other  side.  Each  of  us  was,  as  .usual,  armed  with  his 
own  axe;  and, carrying  with  us  suitable  stakes, my  guide 
and  myself  entered  upon  this  portion  of  the  glacier  on  the 
morning  of  the  19th  of  August. 

I  was  surprised  on  entering  to  find  some  veins  of  white 
ice,  which  from  their  position  and  aspect  appeared  to  be 
derived  from  the  Glacier  du  Ge'ant;  but  to  these  I  shall 
subsequently  refer.  Our  work  was  extremely  difficult ; 
we  penetrated  to  some  distance  along  one  line,  but 
were  finally  forced  back,  and  compelled  to  try  another. 
Right  and  left  of  us  were  profound  fissures,  and  once 


1857.]  "NOUS  NOUS   TROUVERONS  PERDUS."  89 

a  cone  of  ice  forty  feet  high  leaned  quite  over  our  track. 
In  front  of  us  was  a  second  leaning  mass  borne  by  a 
mere  stalk,  and  so  topheavy  that  one  wondered  why  the 
slight  pedestal  on  which  it  rested  did  not  suddenly  crack 
across.  We  worked  slowly  forwards,  and  soon  found  our- 
selves in  the  shadow  of  the  topheavy  mass  above  referred 
to ;  and  from  which  I  escaped  with  a  wounded  hand, 
caused  by  over-haste.  Simond  surmounted  the  next 
ridge  and  exclaimed,  "Nous  nous  trouverons  perdus  !  "  I 
reached  his  side,  and  on  looking  round  the  place  saw  that 
there  was  no  footing  for  man.  The  glacier  here,  as  shown 
.in  the  frontispiece,  was  cut  up  into  thin  wedges,  separated 
from  each  other  by  profound  chasms,  and  the  wedges  were 
so  broken  across  as  to  render  creeping  along  their  edges 
quite  impossible.  Thus  brought  to  a  stand,  I  fixed  a 
stake  at  the  point  where  we  were  forced  to  halt,  and  re- 
treated along  edges  of  detestable  granular  ice,  which  fell 
in  showers. into  the  crevasses  when  struck  by  the  axe.  At 
one  place  an  exceedingly  deep  fissure  was  at  our  left, 
which  was  joined,  at  a  sharp  angle,  by  another  at  our 
right,  and  we  were  compelled  to  cross  at  the  place  of  in- 
tersection :  to  do  this  we  had  to  trust  ourselves  to  a  pro- 
jecting knob  of  that  vile  rotten  ice  which  I  had  learned 
to  fear  since  my  experience  of  it  on  the  Col  du  Ge'ant. 
We  finally  escaped,  and  set  out  our  line  at  another  place, 
where  the  glacier,  though  badly  cut,  was  not  impassable. 
On  the  20th,  we  made  a  series  of  final  measurements  at 
the  Tacul,  and  determined  the  motion  of  two  lines  which 
we  had  set  out  upon  the  previous  day.  On  the  21st,  we 
quitted  the  Montanvert ;  I  had  been  there  from  the  15th 
of  July,  and  the  longer  I  remained  the  better  I  liked  the 
establishment  and  the  people  connected  with  it.  It  was 
then  managed  by  Joseph  Tairraz  and  Jules  Charlet,  both 
of  whom  showed  us  every  attention.  In  1858  and  1859  I 
had  occasion  to  revisit  the  establishment,  which  was  then 


90  FAREWELL  TO   THE  MONTANVERT.  [1857. 

managed  by  Jules  and  his  brother,  and  found  in  it  the 
same  good  qualities.  During  my  winter  expedition  of 
1859  I  also  found  the  same  readiness  to  assist  me  in  every 
possible  way ;  honest  Jules  expressing  his  willingness  to 
ascend  through  the  snow  to  the  auberge  if  I  thought  his 
presence  would  in  any  degree  contribute  to  my  comfort. 

We  crossed  the  glacier,  and  descended  by  the  Chapeau 
to  the  Cascade  des  Bois,  the  inclination  of  which  and  of 
the  lower  portion  of  the  glacier  we  then  determined.  The 
day  was  magnificent.  Looking  upwards,  the  Aiguilles  de 
Charmoz  and  du  Dru  rose  right  and  left  like  sentinels  of 
the  valley,  while  in  front  of  us  the  ice  descended  the  steep, 
a  bewildering  mass  of  crags  and  chasms.  At  the  other 
side  was  the  pine-clad  slope  of  the  Montanvert.  Further 
on  the  Aiguille  du  Midi  threw  its  granite  pyramid  between 
us  and  Mont  Blanc ;  on  the  Dome  du  Gout£  the  seracs  of 
the  mountain  were  to  be  seen,  while  issuing  as  if  from  a 
cleft  in  the  mountain  side  the  Glacier  des  Bossons  thrust 
through  the  black  pines  its  snowy  tongue.  Below  us  was 
the  beautiful  valley  of  Chamouni  itself,  through  which  the 
Arve  and  Arveiron  rushed  like  enlivening  spirits.  We 
finally  examined  a  grand  old  moraine  produced  by  a  Mer 
de  Glace  of  other  ages,  when  the  ice  quite  crossed  the 
valley  of  Chamouni  and  abutted  against  the  opposite 
mountain-wall. 

Simond  had  proved  himself  a  very  valuable  assistant ; 
he  was  intelligent  and  perfectly  trustworthy  ;  and  though 
the  peculiar  nature  of  my  work  sometimes  caused  me  to 
attempt  things  against  which  his  prudence  protested,  he 
lacked  neither  strength  nor  courage.  On  reaching  Cha- 
mouni and  adding  up  our  accounts,  I  found  that  I  had  not 
sufficient  cash  to  pay  him ;  money  was  waiting  for  me  at 
the  post-office  in  Geneva,  and  thither  it  was  arranged  that 
my  friend  Hirst  should  proceed  next  morning,  while  I  was 
to  await  the  arrival  of  the  money  at  Chamouni.  My  guide 


1857.]  EDOUARD   SIMOND.  91 

heard  of  this  arrangement,  and  divined  its  cause :  he 
carne  to  me,  and  in  the  most  affectionate  manner  begged 
of  me  to  accept  from  him  the  loan  of  500  francs.  Though 
I  did  not  need  the  loan,  the  mode  in  which  it  was  offered 
to  me  augmented  the  kindly  feelings  which  I  had  long 
entertained  towards  Simond,  and  I  may  add  that  my  in- 
tercourse with  him  since  has  served  merely  to  confirm 
my  first  estimate  of  his  worthiness. 


92  DOUBTS    REGARDING   STRUCTURE.  [1853. 


EXPEDITION    OF    1858. 

(13.) 

I  had  confined  myself  during  the  summer  of  1857  to 
the  Mer  de  Glace  and  its  tributaries,  desirous  to  make  my 
knowledge  accurate  rather  than  extensive.  I  had  made 
the  acquaintance  of  all  accessible  parts  of  the  glacier,  and 
spared  no  pains  to  master  both  the  details  and  the  meaning 
of  the  laminated  structure  of  the  ice,  but  I  found  no  fact 
upon  which  I  could  take  my  stand  and  say  to  an  advocate 
of  an  opposing  theory,  "  This  is  unassailable."  In  experi- 
mental science  we  have  usually  the  power  of  changing  the 
conditions  at  pleasure  ;  if  Nature  does  not  reply  to  a  ques- 
tion, we  throw  it  into  another  form ;  a  combining  of  condi- 
tions is,  in  fact,  the  essence  of  experiment.  To  meet  the 
requirements  of  the  present  question,  I  could  not  twist  the 
same  glacier  into  various  shapes,  and  throw  it  into  differ- 
ent states  of  strain  and  pressure  ;  but  I  might,  by  visiting 
many  glaciers,  find  all  needful  conditions  fulfilled  in  detail, 
and  by  observing  these  I  hoped  to  confer  upon  the  subject 
the  character  and  precision  of  a  true  experimental  inquiry. 

The  summer  of  1858  was  accordingly  devoted  to  this 
purpose,  when  I  had  the  good  fortune  to  be  accompanied 
by  Professor  Ramsay,  the  author  of  some  extremely  in- 
teresting papers  upon  ancient  glaciers.  Taking  Zurich, 
Schaffhausen,  and  Lucerne  in  our  way,  we  crossed  the 
Briinig  on  the  22nd  of  July,  and  met  my  guide,  Christian 
Lauener,  at  Meyringen.  On  the  23rd  we  visited  the 
glacier  of  Rosenlaui,  and  the  glacier  of  the  Schwartz- 
wald,  and  reached  Grindelwald  in  the  evening  of  the  same 
day.  My  expedition  with  Mr.  Huxley  had  taught  me 
that  the  Lower  Grindelwald  Glacier  was  extremely  in- 


1858.]  A   GLOOMY  PROSPECT.  93 

structive,  and  I  was  anxious  to  see  many  parts  of  it  once 
more ;  this  I  did,  in  company  with  Ramsay,  and  we  also 
spent  a  day  upon  the  upper  glacier,  after  which  our  path 
lay  over  the  Strahleck  to  the  glaciers  of  the  Aar  and  of 
the  Rhone. 


PASSAGE   OF   THE   STRAHLECK. 

(14.) 

ON  Monday,  the  26th  of  July,  we  were  called  at  4  A.  M., 
and  found  the  weather  very  unpromising,  but  the  two 
mornings  which  preceded  it  had  also  been  threatening 
without  any  evil  result.  There  was,  it  is  true,  something 
more  than  usually  hostile  in  the  aspect  of  the  clouds, 
which  sailed  sullenly  from  the  west,  and  smeared  the  air 
and  mountains  as  if  with  the  dirty  smoke  of  a  manufac- 
turing town.  We  despatched  our  coffee,  went  down  to  the 
bottom  of  the  Grindelwald  valley,  up  the  opposite  slope, 
and  were  soon  amid  the  gloom  of  the  pines  which  partially 
cover  it.  On  emerging  from  these,  a  watery  gleam  on 
the  mottled  head  of  the  Eiger  was  the  only  evidence  of 
direct  sunlight  in  that  direction.  To  our  left  was  the 
Wetterhorn,  surrounded  by  wild  and  disorderly  clouds, 
through  the  fissures  of  which  the  morning  light  glared 
strangely.  For  a  time  the  Heisse  Platte  was  seen,  a  dark 
brown  patch  amid  the  ghastly  blue  which  overspread  the 
surrounding  slopes  of  snow.  The  clouds  once  rolled  up, 
and  revealed  for  a  moment  the  summits  of  the  Viescher- 
horner  ;  but  they  immediately  settled  down  again,  and  hid 
!  the  mountains  from  top  to  base.  Soon  afterwards  they 
:  drew  themselves  partially  aside,  and  a  patch  of  blue  over 
the  Strahleck  gave  us  hope  and  pleasure.  As  we  ascended, 


94  ICE  CASCADE  AND  PROTUBERANCES.  [1858. 

the  prospect  in  front  of  us  grew  better,  but  that  behind 
us  —  and  the  wind  came  from  behind  —  grew  worse. 
Slowly  and  stealthily  the  dense  neutral-tint  masses  crept 
along  the  sides  of  the  mountains,  and  seemed  to  dog  us 
like  spies  ;  while  over  the  glacier  hung  a  thin  veil  of  fog, 
through  which  gleamed  the  white  minarets  of  the  ice. 

When  we  first  spoke  of  crossing  the  Strahleck,  Lauener 
said  it  would  be  necessary  to  take  two  guides  at  least ;  but 
after  a  day's  performance  on  the  ice  he  thought  we  might 
manage  very  well  by  taking,  in  addition  to  himself,  the 
herd  of  the  alp,  over  the  more  difficult  part  of  the  pass. 
He  had  further  experience  of  us  on  the  second  day, 
and  now,  as  we  approached  the  herd's  hut,  I  was  amused 
to  hear  him  say  that  he  thought  any  assistance  beside  his 
own  unnecessary.  Relying  upon  ourselves,  therefore,  we 
continued  our  route,  and  were  soon  upon  the  glacier,  which 
had  been  rendered  smooth  and  slippery  through  the  re- 
moval of  its  disintegrated  surface  by  the  warm  air.  Cross- 
ing the  Strahleck  branch  of  the  glacier  to  its  left  side,  we 
climbed  the  rocks  to  the  grass  arid  flowers  which  clothe  the 
slopes  above  them.  Our  way  sometimes  lay  over  these, 
sometimes  along  the  beds  of  streams,  across  turbulent 
brooks,  and  once  around  the  face  of  a  cliff,  which  afforded 
us  about  an  inch  of  ledge  to  stand  upon,  and  some  protrud- 
ing splinters  to  lay  hold  of  by  the  hands.  Having  reached 
a  promontory  which  commanded  a  fine  view  of  the  glacier, 
and  of  the  ice  cascade  by  which  it  was  fed,  I  halted,  to 
check  the  observations  already  made  from  the  side  of  the 
opposite  mountain.  Here,  as  there,  cliffy  ridges  were  seen 
crossing  the  cascade  of  the  glacier,  with  interposed  spaces 
of  dirt  and  de*bris,  —  the  former  being  toned  down,  and  the 
latter  squeezed  towards  the  base  of  the  fall,  until  finally 
the  ridges  swept  across  the  glacier,  in  gentle  swellings,  from 
side  to  side ;  while  the  valleys  between  them,  holding  the 
principal  share  of  the  superficial  impurity,  formed  the 


1858.]     DIRT-BANDS  OF  THE   STRAHLECK  BRANCH.         95 

cradles  of  the  so-called  Dirt-Bands.  These  swept  con- 
centric with  the  protuberances  across  'the  glacier,  and 
remained  upon  its  surface  even  after  the  swellings  had 
disappeared.  The  swifter  flow  of  the  centre  of  the  glacier 
tends  of  course  incessantly  to  lengthen  the  loops  of  the 
bands,  and  to  thrust  the  summits  of  the  curves  which  they 
form  more  and  more  in  advance  of  their  lateral  portions. 
The  depressions  between  the  protuberances  appeared  to 
be  furrowed  by  minor  wrinkles,  as  if  the  ice  of  the  depres- 
sions had  yielded  more  than  that  of  the  protuberances. 
This,  I  think,  is  extremely  probable,  though  it  has  never 
yet  been  proved.  Three  stakes,  placed,  one  on  the  summit, 
another  on  the  frontal  slope,  and  another  at  the  base  of  a 
protuberance,  would,  I  think,  move  with  unequal  velocities. 
They  would,  I  think,  shew  that,  upon  the  large  and  gene- 
ral motion  of  the  glacier,  smaller  motions  are  superposed, 
as  minor  oscillations  are  known  to  cover  parasitically  the 
large  ones  of  a  vibrating  string.  Possibly,  also,  the  dirt- 
bands  may  owe  something  to  the  squeezing  of  impuri- 
ties out  of  the  glacier  to  its  surface  in  the  intervals 
between  the  swellings.  From  our  present  position  we 
could  also  see  the  swellings  on  the  Yiescherhorner  branch 
of  the  glacier,  in  the  valleys  between  which  coarse  shingle 
and  debris  were  collected,  which  would  form  dirt-bands  if 
they  could.  On  neither  branch,  however,  do  the  bands 
attain  the  definition  and  beauty  which  they  possess  upon 
the  Mer  de  Glace. 

After  an  instructive  lesson  we  faced  our  task  once  more, 
passing  amid  crags  and  boulders,  and  over  steep  moraines, 
from  which  the  stones  rolled  down  upon  the  slightest  dis- 
turbance. While  crossing  a  slope  of  snow  with  an  inclina- 
tion of  45°,  my  footing  gave  way,  I  fell,  but  turned  promptly 
on  my  face,  dug  my  staff  deeply  into  the  snow,  and  arrested 
the  motion  before  I  had  slid  a  dozen  yards.  Ramsay 
was  behind  me,  speculating  whether  he  should  be  able  to 


96  ICE  CLIFTS  THROUGH  THE  FOG.  [1858. 

pass  the  same  point  without  slipping  ;  before  he  reached 
it,  however,  the  "snow  yielded,  he  fell,  and  slid  swiftly 
downwards.  Lauener,  whose  attention  had  been  aroused 
by  my  fall,  chanced  to  be  looking  round  when  Ranlsay's 
footing  yielded.  With  the  velocity  of  a  projectile  he  threw 
himself  upon  my  companion,  seized  him,  and  brought  him 
to  rest  before  he  had  reached  the  bottom  of  the  slope.  The 
act  made  a  very  favourable  impression  upon  me,  it  was  so 
prompt  and  instinctive.  An  eagle  could  not  swoop  upon  its 
prey  with  more  directness  of  aim  and  swiftness  of  execution. 
While  this  went  on  the  clouds  were  playing  hide  and 
seek  with  the  mountains.  The  ice-crags  and  pinnacles  to 
our  left,  looming  through  the  haze,  seemed  of  gigantic  pro- 
portions, reminding  one  of  the  Hades  of  Byron's  '  Cain.' 

"  How  sunless  and  how  vast  are  these  dim  realms  !  " 

We  climbed  for  some  time  along  the  moraine  which 
flanks  the  cascade,  and  on  reaching  the  level  of  the  brow 
Lauener  paused,  cast  off  his  knapsack,  and  declared  for 
breakfast.  While  engaged  with  it  the  dense  clouds  which 
had  crammed  the  gorge  and  obscured  the  mountains,  all 
melted  away,  and  a  scene  of  indescribable  magnificence 
was  revealed.  Overhead  the  sky  suddenly  deepened  to 
dark  blue,  and  against  it  the  Finsteraarhorn  projected  his 
dark  and  mighty  mass.  Brown  spurs  jutted  from  the 
mountain,  and  between  them  were  precipitous  snow-slopes, 
fluted  by  the  descent  of  rocks  and  avalanches,  and  broken 
into  ice-precipices  lower  down.  Eight  in  front  of  us,  and 
from  its  proximity  more  gigantic  to  the  eye,  was  the 
Shreckhorn,  while  from  couloirs  and  mountain-slopes 
the  matter  of  glaciers  yet  to  be  was  poured  into  the 
vast  basin  on  the  rim  of  which  we  now  stood. 

This  it  was  next  our  object  to  cross ;  our  way  lying 
in  part  through  deep  snow-slush,  the  scene  changing 
perpetually  from  blue  heaven  to  gray  haze  which  massed 
itself  at  intervals  in  dense  clouds  about  the  moun- 


1838.]  MUTATIONS   OF  THE   CLOUDS.  97 

tains.  After  crossing  the  basin,  our  way  lay  partly  over 
slopes  of  snow,  partly  over  loose  shingle,  and  at  one  place 
along  the  edge  of  a  formidable  precipice  of  rock.  We  sat 
down  sometimes  to  rest,  and  during  these  pauses,  though 
they  were  very  brief,  the  scene  had  time  to  go  through 
several  of  its  Protean  mutations.  At  one  moment  all 
would  be  perfectly  serene,  no  cloud  in  the  transparent  air 
to  tell  us  that  any  portion  of  it  was  in  motion,  while  the 
blue  heaven  threw  its  flattened  arch  over  the  magnificent 
amphitheatre.  Then  in  an  instant,  from  some  local  caul- 
dron, the  vapour  would  boil  up  suddenly,  eddying  wildly  in 
the  air,  which  a  moment  before  seemed  so  still,  and  envel- 
oping the  entire  scene.  Thus  the  space  enclosed  by  the 
Finsteraarhorn,  the  Viescherhorner,  and  the  Shreckhorn, 
would  at  one  moment  be  filled  with  fog  to  the  mountain 
heads,  every  trace  of  which  a  few  minutes  sufficed  to 
sweep  away,  leaving  the  unstained  blue  of  heaven  behind 
it,  and  the  mountains  showing  sharp  and  jagged  outlines 
in  the  glassy  air.  One  might  be  almost  led  to  imagine 
that  the  vapour  molecules  endured  a  strain  similar  to  that 
of  water  cooled  below  its  freezing  point,  or  heated  beyond 
its  boiling  point ;  and  that,  on  the  strain  being  relieved 
by  the  sudden  yielding  of  the  opposing  force,  the  parti- 
cles rushed  together,  and  thus  filled  in  an  instant  the 
clear  atmosphere  with  aqueous  precipitation. 

I  had  no  idea  that  the  Strahleck  was  so  fine  a  pass. 
Whether  it  is  the  quality  of  my  mind  to  take  in  the  glory 
of  the  present  so  intensely  as  to  make  me  forgetful  of  the 
glory  of  the  past,  I  know  not,  but  it  appeared  to  me  that 
I  had  never  seen  anything  finer  than  the  scene  from  the 
summit.  The  amphitheatre  formed  by  the  mountains 
seemed  to  me  of  exceeding  magnificence ;  nor  do  I  think 
i  that  my  feeling  was  subjective  merely ;  for  the  simple 
magnitude  of  the  masses  which  built  up  the  spectacle 
would  be  sufficient  to  declare  its  grandeur.  Looking 
7 


98  DESCENT  OF  THE   CRAGS.  [1858. 

down  towards  the  Glacier  of  the  Aar,  a  scene  of  wild 
beauty  and  desolation  presented  itself.  Not  a  trace  of 
vegetation  could  be  seen  along  the  whole  range  of  the 
bounding  mountains  ;  glaciers  streamed  from  their  shoul- 
ders into  the  valley  beneath,  where  they  welded  themselves 
to  form  the  Finsteraar  affluent  of  the  Unteraar  glacier. 

After  a  brief  pause,  Lauener   again  strapped  on  his 
knapsack,  and  tempered  both  will  and  muscles  by  the  re- 
mark, that  our  worst  piece  of  work  was  now  before  us. 
From  the  place  where  we  sat,  the  mountain  fell  precipi- 
tously for  several  hundred  feet ;  and  down  the  weathered 
crags,  and  over  the  loose  shingle  which  encumbered  their 
ledges,  our  route  now  lay.     Lauener  was  in  front,  cool  and 
collected,  lending  at  times  a  hand  to  Ramsay,  and  a  word 
of  encouragement  to  both  of  us,  while  I  brought  up  the 
rear.     I  found  my  full  haversack  so  inconvenient  that  I 
once  or  twice  thought  of  sending  it  down  the  crags  in  ad- 
vance of  me,  but  Lauener  assured  me  that  it  would  be 
utterly  destroyed  before  reaching  the  bottom.     My  com- 
plaint against  it  was,  that  at  critical  places  it  sometimes 
came  between  me  and  the  face  of  the  cliff,  pushing  me  away 
from  the  latter  so  as  to  throw  my  centre  of  gravity  almost 
beyond  the  base  intended  to  support  it.     We  came  at  length 
upon  a  snow-slope,  which  had  for  a  time  an  inclination  of 
50° ;  then  once  more  to  the  rocks  ;  again  to  the  snow,  which 
was  both  steep  and  deep.     Our  batons  were  at  least  six  feet 
long :  we  drove  them  into  the  snow  to  secure  an  anchor- 
age, but  they  sank  to  their  very  ends,  and  we  merely  re- 
tained a  length  of  them  sufficient  for  a  grasp.     This  slope 
was  intersected  by  a  so-called  Bergschrund,  the  lower  por- 
tion of  the  slope  being  torn  away  from  its  upper  portion  so 
as  to  form  a  crevasse  that  extended  quite  round  the  head 
of  the  valley.     We  reached  its  upper  edge  ;  the  chasm  was 
partially  filled  with  snow,  which  brought  its  edges  so  near 
that  we  cleared  it  by  a  jump.     The  rest  of  the  slope  was 


1858.]  THROUGH  GLOOM  TO   THE  GKIMSEL.  99 

descended  by  a  glissade.  Each  sat  down  upon  the  snow, 
and  the  motion,  once  commenced,  swiftly  augmented  to 
the  rate  of  an  avalanche,  and  brought  us  pleasantly  to  the 
bottom. 

As  we  looked  from  the  heights,  we  could  see  that  the 
valley  through  which  our  route  lay  was  filled  with  gray 
fog :  into  this  we  soon  plunged,  and  through  it  we  made 
our  way  towards  the  Abschwung.  The  inclination  of  the 
glacier  was  our  only  guide,  for  .we  could  see  nothing. 
Reaching  the  confluence  of  the  Finsteraar  and  Lauteraar 
branches,  we  went  downwards  with  long  swinging  strides, 
close  alongside  the  medial  moraine  of  the  trunk  glacier. 
The  glory  of  the  morning  had  its  check  in  the  dull  gloom 
of  the  evening.  Across  streams,  amid  dirt-cones  and  gla- 
cier-tables, and  over  the  long  reach  of  shingle  which  cov- 
ers the  end  of  the  glacier,  we  plodded  doggedly,  and 
reached  the  Grimsel  at  7  P.  M.,  the  journey  having  cost  a 
little  more  than  14  hours. 


(15.) 

We  made  the  Grimsel  our  station  for  a  day,  which  was 
spent  in  examining  the  evidences  of  ancient  glacier  action 
in  the  valley  of  Hasli.  Near  the  Hospice,  but  at  the  op- 
posite side  of  the  Aar,  rises  a  mountain-wall  of  hard  granT 
ite,  on  which  the  flutings  and  groovings'are  magnificently 
preserved.  After  a  little  practice  the  eye  can  trace  with 
the  utmost  precision  the  line  which  marks  the  level  of  the 
ancient  ice :  above  this  the  crags  are*sharp  and  rugged  ; 
while  below  it  the  mighty  grinder  has  rubbed  off  the  pin- 
nacles of  the  rocks  and  worn  their  edges  away.  The 
height  to  which  this  action  extends  must  be  nearly  two 
thousand  feet  above  the  bed  of  the  present  valley.  It  is 
also  easy  to  see  the  depth  to  which  the  river  has  worked 


100  ANCIENT   GLACIER  ACTION.  [1858. 

its  channel  into  the  ancient  rocks.  In  some  cases  the 
road  from  Guttanen  to  the  Grimsel  lay  right  over  the  pol- 
ished rocks,  asperities  being  supplied  by  the  chisel  of  man 
in  order  to  prevent  travellers  from  slipping  on  their  slopes. 
Here  and  there  also  huge  protuberant  crags  were  rounded  | 
into  domes  almost  as  perfect  as  if  chiselled  by  art.  To 
both  my  companion  and  myself  this  walk  was  full  of  in- 
struction and  delight. 

On  the  28th  of  July  we  crossed  the  Grimsel  pass,  and  ji 
traced  the  scratchings  to  the  very  top  of  it.  Ramsay  re- 
marked that  their  direction  changed  high  up  the  pass,  as 
if  a  tributary  from  the  summit  had  produced  them,  while  | 
lower  down  they  merged  into  the  general  direction  of  the 
glacier  which  had  filled  the  principal  valley.  From  the 
summit  of  the  Mayenwand  we  had  a  clear  view  of  the 
glacier  of  the  Rhone ;  and  to  see  the  lower  portion  of 
this  glacier  to  advantage  no  better  position  can  be 
chosen.  The  dislocation  of  its  cascade,  the  spreading 
out  of  the  ice-  below,  its  system  of  radial  crevasses,  and 
the  transverse  sweep  of  its  structural  groovings,  may  all 
be  seen.  A  few  hours  afterwards  we  were  amid  the  wild 
chasms  at  the  brow  of  the  ice-fall,  where  we  worked  our 
way  to  the  centre  of  the  ice,  but  were  unable  to  attain 
the  opposite  side. 

Having  examined  the  glacier  both  above  and  below  the 
cascade,  we  went  down  the  valley  to  Yiesch,  and  ascended 
thence,  on  the  304,h  of  July,  to  the  HOtel  Jungfrau  on  the 
slopes  of  the  ^Bggischhorn.  On  the  following  day  we 
climbed  to  the  summit  of  the  mountain,  and  from  a  shel- 
tered nook  enjoyec^  the  glorious  prospect  which  it  com- 
mands. The  wind  was  strong,  and  fleecy  clouds  flew 
over  the  heavens ;  some  of  which,  as  they  formed  and 
dispersed  themselves  about  the  flanks  of  the  Aletschhorn, 
showed  extraordinary  iridescences. 

The  sunbeams  called  us  early  on  the  morning  of  the  1st 


1858.]  THE   MARJELEN   SEE.  101 

of  August.  No  cloud  rested  on  the  opposite  range  of  the 
Yalais  mountains,  but  on  looking  towards  the  j5Cggischhorn 
we  found  a  cap  upon  its  crest ;  we  looked  again, — the  cap 
had  disappeared  and  a  serene  heaven  stretched  overhead. 
As  we  breasted  the  alp  the  m'oon  was  still  in  the  sky, 
paling  more  and  more  before  the  advancing  day ;  a  single 
hawk  swung  in  the  atmosphere  above  us  ;  clear  streams 
babbled  from  the  hills,  the  louder  sounds  reposing  on  a 
base  of  music  ;  while  groups  of  cows  with  tinkling  bells 
browsed  upon  the  green  alp.  Here  and  there  the  grass 
was  dispossessed,  and  the  flanks  of  the  mountain  were 
covered  by  the  blocks  which  had  been  cast  down  from  the 
summit.  On  reaching  the  plateau  at  the  base  of  the  final 
pyramid,  we  rounded  the  mountain  to  the  right  and  came 
over  the  lonely  and  beautiful  Marjelen  See.  No  doubt 
the  hollow  which  this  lake  fills  had  been  scooped  out  in 
former  ages  by  a  branch  of  the  Aletsch  glacier  ;  but  long- 
ago  the  blue  ice  gave  place  to  blue  water.  The  glacier 
bounds  it  at  one  side  by  a  vertical  wall  of  ice  sixty  feet 
in  height :  this  is  incessantly  undermined,  a  roof  of  crystal 
being  formed  over  the  water,  till  at  length  the  projecting 
mass,  becoming  too  heavy  for  its  own  rigidity,  breaks  and 
tumbles  into  the  lake.  Here,  attacked  by  sun  and  air, 
its  blue  surface  is  rendered  dazzlingly  white,  and  several 
icebergs  of  this  kind  now  floated  in  the  sunlight ;  the 
water  was  of  a  glassy  smoothness,  and  in  its  blue  depths 
each  ice  mass  doubled  itself  by  reflection.* 

The  Aletsch  is  the  grandest  glacier  in  the  Alps :  over 
it  we  now  stood,  while  the  bounding  mountains  poured 
yast  feeders  into  the  noble  stream.  The  Jungfrau  was  in 
front  of  us  without  a  cloud,  and  apparently  so  near  that  I 
proposed  to  my  guide  to  try  it  without  further  prepara- 
tion. He  was  enthusiastic  at  first,  but  caution  afterwards 

!  *  A  painting  of  this  exquisite  lake  has  been  recently  executed  by  Mr. 
George  Barnard. 


102  THE  ALETSCH  GLACIER.  .[1858. 

got  the  better  of  his  courage.  At  some  distance  up  the 
glacier  the  snow-line  was  distinctly  drawn,  and  from  its 
edge  upwards  the  mighty  shoulders  of  the  hills  were  heavy 
laden  with  the  still  powdery  material  of  the  glacier. 

Amid  blocks  and  debris  we  descended  to  the  ice  :  the 
portion  of  it  which  bounded  the  lake  had  been  sapped, 
and  a  space  of  a  foot  existed  between  ice  and  water  : 
numerous  chasms  were  formed  here,  the  mass  being  thus 
broken,  preparatory  to  being  sent  adrift  upon  the  lake. 
We  crossed  the  glacier  to  its  centre,  and  looking  down  it 
the  grand  peaks  of  the  Mischabel,  the  noble  cone  of  the 
Weisshorn,  and  the  dark  and  stern  obelisk  of  the  Mat- 
terhorn,  formed  a  splendid  picture.     Looking  upwards, 
a  series  of  most  singularly  contorted  dirt-bands  revealed 
themselves  upon  the  surface  of  the  ice.    I  sought  to  trace 
them  to  their  origin,  but  was  frustrated  by  the  snow  which 
overspread  the  upper  portion  of  the  glacier.     Along  this 
we  marched  for  three  hours,  and  came  at  length  to  the 
junction  of  the  four  tributary  valleys  which  pour  their 
frozen  streams  into  the  great  trunk  valley.-    The  glory 
of  the  day,  and  that  joy  of  heart  which  perfect  health 
confers,  may  have  contributed  to  produce  the  impression,! 
but  I  thought  I  had  never  seen  anything  to  rival  in  mag-: 
nificence  the  region  in  the  heart  of  which  we  now  found1 
ourselves.     We  climbed  the  mountain  on  the  right-hand  i 
side  of  the  glacier,  where,  seated  amid  the  riven  and; 
weather-worn  crags,  we  fed  our  souls  for  hours  on  the 
transcendent  beauty  of  the  scene. 

We  afterwards  redescended  to  the  glacier,  which  at  this 
place  was  intersected  by  large  transverse  crevasses,  many 
of  which  were  apparently  filled  with  snow,  while  over 
others  a  thin  and  treacherous  roof  was  thrown.     In  som 
cases  the  roof  had  broken  away,  and  revealed  rows  o 
icicles  of  great  length  and  transparency  pendent  from  th 
edges.     We  at  length  turned  our  faces  homewards,  an 


1858.]*  A  CHAMOIS  DECEIVED.  103 

looking  down'  the  glacier  I  saw  at  a  great  distance  some- 
thing moving  on  the  ice.  I  first  thought  it  was  a  man, 
though  it  seemed  strange  that  a  man  should  be  there 
alone.  On  drawing  my  guide's  attention  to  it,  he  at  once 
pronounced  it  to  be  a  chamois,  and  I  with  my  telescope 
immediately  verified  his  statement.  The  creature  bound- 
ed up  the  glacier  at  intervals,  and  sometimes  the  vigour 
of  its  spring  showed  that  it  had  projected  itself  over  a 
crevasse.  It  approached  us  sometimes  at  full  gallop : 
then  would  stop,  look  toward  us,  pipe  loudly,  and  com- 
mence its  race  once  more.  It  evidently  made  the  recipro- 
cal mistake  to  my  own,  imagining  us  to  be  of  its  own  kith 
and  kin.  We  sat  down  upon  the  ice  the  better  to  conceal 
our  forms,  and  to  its  whistle  our  guide  whistled  in  reply. 
A  joyous  rush  was  the  creature's  first  response  to  the  sig- 
nal ;  but  it  afterwards  began  to  doubt,  and  its  pauses 
became  more  frequent.  Its  form  at  times  was  extremely 
graceful,  the  head  erect  in  the  air,  its  apparent  upright- 
ness being  augmented  by  the  curvature  which  threw  its 
horns  back.  I  watched  the  animal  through  my  glass  un- 
til I  could  see  the  glistening  of  its  eyes ;  but  soon  after- 
wards it  made  a  final  pause,  assured  itself  of  its  error, 
and  flew  with  the  speed  of  the  wind  to  its  refuge  in  the 
mountains. 


104  MY   GUIDE.  J1858. 


ASCENT  OF   THE    FINSTERAARHORN,   1858. 
(16.) 

SINCE  my  arrival  at  the  hotel  on  the  30th  of  July  I  had 
once  or  twice  spoken  about  ascending  the  Finsteraarhorn, 
and  on  the  2nd  of  August  my  host  advised  me  to  avail 
myself  of  the  promising  weather.  A  guide,  named  Ben- 
nen,  was  attached  to  the  hotel,  a  remarkable-looking  man, 
between  30  and  40  years  old,  of  middle  stature,  but  very 
strongly  built.  His  countenance  was  frank  and  firm, 
while  a  light  of  good-nature  at  times  twinkled  in  his  eye. 
Altogether  the  man  gave  me  the  impression  of  physical 
strength,  combined  with  decision  of  character.  The  pro- 
prietor had  spoken  to  me  many  times  of  the  strength  and 
courage  of  this  man,  winding  up  his  praises  of  him  by 
the  assurance  that,  if  I  were  killed  in  Bennen's  company, 
there  would  be  two  lives  lost,  for  that  the  guide  would 
assuredly  sacrifice  himself  in  the  effort  to  save  his  Herr. 

He  was  called,  and  I  asked  him  whether  he  would  ac- 
company me  alone  to  the  top  of  the  Finsteraarhorn.  To 
this  he  at  first  objected,  urging  the  possibility  of  his  having 
to  render  me  assistance,  and  the  great  amount  of  labour 
which  this  might  entail  upon  him  ;  but  this  was  overruled 
by  my  engaging  to  follow  where  he  led,  without  asking  him 
to  render  me  any  help  whatever.  He  then  agreed  to  make 
the  trial,  stipulating,  however,  that  he  should  not  have 
much  to  carry  to  the  cave  of  the  Faulberg,  where  we  were 
to  spend  the  night.  To  this  I  cordially  agreed,  and  sent 
on  blankets,  provisions,  wood,  and  hay,  by  two  porters. 

My  desire,  in  part,  was  to  make  a  series  of  observations 
at  the  summit  of  the  mountain,  while  a  similar  series  was 
made  by  Professor  Ramsay  in  the  valley  of  the  Rhone,  near 


1858.]  IRIDESCENT  CLOUD.  105 

Viesch,  with  a  view  to  ascertaining  the  permeability  of  the 
lower  strata  of  the  atmosphere  to  the  radiant  heat  of  the 
sun.  During  the  forenoon  of  the  2nd  I  occupied  myself 
with  my  instruments,  and  made  the  proper  arrangements 
with  Ramsay.  I  tested  a  mountain-thermometer  which 
Mr.  Casella  had  kindly  lent  me,  and  found  the  boiling 
point  of  water  on  the  dining-room  table  of  the  hotel  to  be 
199.29°  Fahrenheit.  At  about  three  o'clock  in  the  after- 
noon we  quitted  the  hotel,  and  proceeded  leisurely  with 
our  two  guides  up  the  slope  of  the  ^Eggischhorn.  We 
once  caught  a  sight  of  the  topmost  pinnacle  of  the  Fin- 
steraarhorn ;  beside  it  was  the  Rothhorn,  and  near  this 
again  the  Oberaarhorn,  with  the  Viescher  glacier  stream- 
ing from  its  shoulders.  On  the  opposite  side  we  could  sec, 
over  an  oblique  buttress  of  the  mountain  on  which  we 
stood,  the  snowy  summit  of  the  Weisshorn  ;  to  the  left  of 
this  was  the  ever  grim  and  lonely  Matterhorn  ;  and  far- 
ther to  the  left,  with  its  numerous  snow-cones-,  each  with 
its  attendant  shadow,  rose  the  mighty  Mischabel.  We 
descended,  and  crossed  the  stream  which  flows  from  the 
Marjelen  See,  into  which  a  large  mass  of  the  glacier  had 
recently  fallen,  and  was  now  afloat  as  an  iceberg.  We 
passed  along  the  margin  of  the  lake,  and  at  the  junction  of 
water  and  ice  I  bade  Ramsay  good  bye.  At  the  commence- 
ment of  our  journey  upon  the  ice,  whenever  we  crossed  a 
crevasse,  I  noticed  Bennen  watching  me ;  his  vigilance, 
however,  soon  diminished,  whence  I  gathered  that  he 
finally  concluded  that  I  was  able  to  take  care  of  myself. 
Clouds  hovered  in  the  atmosphere  throughout  the  whole 
time  of  our  ascent ;  one  smoky-looking  mass  marred  the 
glory  of  the  sunset,  but  at  some  distance  was  another  which 
exhibited  colours  almost  as  rich  and  varied  as  those  of  the 
solar  spectrum.  I  took  the  glorious  banner  thus  unfurled 
as  a  sign  of  hope,  to  check  the  despondency  which  its 
gloomy  neighbour  was  calculated  to  produce. 


106  EVENING  NEAR  THE  JUNGFRAU.  [1858. 

Two  hours'  walking  brought  us  near  our  place  of  rest ; 
the  porters  had  already  reached  it,  and  were  now  return- 
ing. We  deviated  to  the  right,  and,  having  crossed  some 
ice-ravines,  reached  the  lateral  moraine  of  the  glacier,  and 
picked  our  way  between  it  and  the  adjacent  mountain- 
wall.  We  then  reached  a  kind  of  amphitheatre,  crossed 
it,  and,  climbing  the  opposite  slope,  came  to  a  triple  grotto 
formed  by  clefts  in  the  mountain.  In  one  of  these  a  pine- 
fire  was  soon  blazing  briskly,  and  casting  its  red  light 
upon  the  surrounding  objects,  though  but  half  dispelling 
the  gloom  from  the  deeper  portions  of  the  cell.  I  left  the 
grotto,  and  climbed  the  rocks  above  it  to  look  at  the 
heavens.  The  sun  had  quitted  our  firmament,  but  still 
tinted  the  clouds  with  red  and  purple ;  while  one  peak  of 
snow  in  particular  glowed  like  fire,  so  vivid  was  its  illu- 
mination. During  our  journey  upwards  the  Jungfrau 
never  once  showed  her  head,  but,  as  if  in  ill  temper,  had 
wrapped  her  vapoury  veil  around  her.  She  now  looked 
more  good-humoured,  but  still  she  did  not  quite  remove 
her  hood ;  though  all  the  other  summits,  without  a  trace 
of  cloud  to  mask  their  beautiful  forms,  pointed  heaven- 
ward. The  calmness  was  perfect ;  no  sound  of  living 
creature,  no  whisper  of  a  breeze,  no  gurgle  of  water,  no 
rustle  of  debris,  to  break  the  deep  and  solemn  silence. 
Surely,  if  beauty  be  an  object  of  worship,  those  glorious 
mountains,  with  rounded  shoulders  of  the  purest  white, — 
snow-crested  and  star-gemmed,  —  were  well  calculated  to 
excite  sentiments  of  adoration. 

I  returned  to  the  grotto,  where  supper  was  prepared  and 
waiting  for  me.  The  boiling-point  of  water,  at  the  level 
of  the  "  kitchen  "  floor,  I  found  to  be  196°  Fahr.  Nothing 
could  be  more  picturesque  than  the  aspect  of  the  cave 
before  we  went  to  rest.  The  fire  was  gleaming  ruddily.  I 
sat  upon  a  stone  bench  beside  it,  while  Bennen  was  in  front 
with  the  red  light  glimmering  fitfully  over  him.  My 


1858.]  THE   CAVE    OF  FAULBERG.  107 

boiling-water  apparatus,  which  had  just  been  used,  was  in 
the  foreground ;  and  telescopes,  opera-glasses,  haversacks, 
wine-keg,  bottles,  and  mattocks,  lay  confusedly  around. 
The  heavens  continued  to  grow  clearer,  the  thin  clouds, 
which  had  partially  overspread  the  sky,  melting  gradually 
away.  The  grotto  was  comfortable ;  the  hay  sufficient 
materially  to  modify  the  hardness  of  the  rock,  and  my  posi- 
tion at  least  sheltered  and  warm.  One  possibility  re- 
mained that  might  prevent  me  from  sleeping,  —  the  snor- 
ing of  my  companion ;  he  assured  me,  however,  that  he  did 
not  snore,  and  we  lay  down  side  by  side.  The  good  fellow 
took  care  that  I  should  not  be  chilled  ;  he  gave  me  the 
best  place,  by  far  the  best  part  of  the  clothes,  and  may  have 
suffered  himself  in  consequence  ;  but,  happily  for  him, 
he  was  soon  oblivious  of  this.  Physiologists,  I  believe,  have 
discovered  that  it  is  chiefly  during  sleep  that  the  muscles 
are  repaired  ;  and  erelong  the  sound  I  dreaded  announced 
to  me  at  once  the  repair  of  Bennen's  muscles  and  the 
doom  of  my  own.  The  hollow  cave  resounded  to  the  deep- 
drawn  snore.  I  once  or  twice  stirred  the  sleeper,  breaking 
thereby  the  continuity  of  the  phenomenon ;  but  it  in- 
stantly pieced  itself  together  again,  and  went  on  as  before. 
I  had  not  the  heart  to  wake  him,  for  I  knew  that  upon 
him  would  devolve  the  chief  labour  of  the  coming  day. 
At  half-past  one  he  rose  and  prepared  coffee,  and  at  two 
o'clock  I  was  engaged  upon  the  beverage.  We  afterwards 
packed  up  our  provisions  and  instruments.  Bennen  bore 
the  former,  I  the  latter,  and  at  three  o'clock  we  set  out. 

We  first  descended  a  steep  slope  to  the  glacier,  along 
which  we  walked  for  a  time.  A  spur  of  the  Faulberg  jutted 
out  between  us  and  the  ice-laden  valley  through  which  we 
must  pass  ;  this  we  crossed  in  order  to  shorten  our  way 
and  to  avoid  crevasses.  Loose  shingle  and  boulders  over- 
laid the  mountain ;  and  here  and  there  walls  of  rock 
opposed  our  progress,  and  rendered  the  route  far  from 


108  "SHALL   WE   TRY   THE  JTJNGFRAU?"  [1858. 

agreeable.  We  then  descended  to  the  Griinhorn  tributary, 
which  joins  the  trunk  glacier  at  nearly  a  right  angle,  being 
terminated  by  a  saddle  which  stretches  across  from  moun- 
tain to  mountain,  with  a  curvature  as  graceful  and  as 
perfect  as  if  drawn  by  the  instrument  of  a  mathematician. 
The  unclouded  moon  was  shining,  and  the  Jungfrau  was 
before  us  so  pure  and  beautiful,  that  the  thought  of  visiting 
the  "  Maiden  "  without  further  preparation  occurred  to  me. 
I  turned  to  Bennen,  and  said,  "  Shall  we  try  the  Jung- 
frau ?  "  I  think  he  liked  the  idea  well  enough,  though  he 
cautiously  avoided  incurring  any  responsibility.  "  If  you 
desire  it,  I  am  ready,"  was  his  reply.  He  had  never  made 
the  ascent,  and  nobody  knew  anything  of  the  state  of  the 
snow  this  year  ;  but  Lauener  had  examined  it  through  a 
telescope  on  the  previous  day,  and  pronounced  it  dan- 
gerous. In  every  ascent  of  the  mountain  hitherto  made, 
ladders  had  been  found  indispensable,  but  we  had  none. 
I  questioned  Bennen  as  to  what  he  thought  of  the  proba- 
bilities, and  tried  to  extract  some  direct  encouragement 
from  him  ;  but  he  said  that  the  decision  rested  altogether 
with  myself,  and  it  was  his  business  to  endeavour  to  carry 
out  that  decision.  "  We  will  attempt  it,  then,"  I  said,  and 
for  some  time  we  actually  walked  towards  the  Jungfrau. 
A  gray  cloud  drew  itself  across  her  summit,  and  clung 
there.  I  asked  myself  why  I  deviated  from  my  ori- 
ginal intention  ?  The  Finsteraarhorn  was  higher,  and 
therefore  better  suited  for  the  contemplated  observa- 
tions. I  could  in  no  wise  justify  the  change,  and  finally 
expressed  my  scruples.  A  moment's  further  conversation 
caused  us  to  "  right  about,"  and  front  the  saddle  of  the 
Griinhorn. 

The  dawn  advanced.  The  eastern  sky  became  illumi- 
nated and  warm,  and  high  in  the  air  across  the  ridge  in 
front  of  us  stretched  a  tongue  of  cloud  like  a  red  flame, 
and  equally  fervid  in  its  hue.  Looking  across  the  trunk 


J856.]  MAGNIFICENT   SCENE.  109 

glacier,  a  valley  which  is  terminated  by  the  Lotsch  saddle 
was  seen  in  a  straight  line  with  our  route,  and  I  often 
turned  to  look  along  this  magnificent  corridor.  The 
mightiest  mountains  in  the  Oberland  form  its  sides ;  still, 
the  impression  which  it  makes  is  not  that  of  vastness  or 
sublimity,  but  of  loveliness  not  to  be  described.  The  sun 
had  not  yet  smitten  the  snows,  of  the  bounding  moun- 
tains, but  the  saddle  carved  out  a  segment  of  the  heavens 
which  formed  a  background  of  unspeakable  beauty.  Over 
the  rim  of  the  saddle  the  sky  was  deep  orange,  passing 
upwards  through  amber,  yellow,  and  vague  ethereal  green 
to  the  ordinary  firmamental  blue.  Right  above  the  snow- 
curve  purple  clouds  hung  perfectly  motionless,  giving 
depth  to  the  spaces  between  them.  There  was  something 
saintly  in  the  scene.  Anything  more  exquisite  I  had 
never  beheld. 

We  marched  upwards  over  the  smooth  crisp  snow  to  the 
crest  of  the  saddle,  and  here  I  turned  to  take  a  last  look 
along  that  grand  corridor,  and  at  that  wonderful  "  daffodil 
sky."  The  sun's  rays  had  already  smitten  the  snows  of  the 
Aletschhorn  ;  the  radiance  seemed  to  infuse  a  principle  of 
life  and  activity  into  the  mountains  and  glaciers,  but  still 
that  holy  light  shone  forth,  and  those  motionless  clouds 
floated  beyond,  reminding  one  of  that  Eastern  religion 
whose  essence  is  the  repression  of  all  action  and  the  sub- 
stitution for  it  of  immortal  calm.  The  Finsteraarhorn  now 
fronted  us  ;  but  clouds  turbaned  the  head  of  the  giant,  and 
hid  it  from  our  view.  The  wind,  however,  being  north, 
inspired  us  with  a  strong  hope  that  they  would  melt  as 
the  day  advanced.  I  have  hardly  seen  a  finer  ice-field  than 
that  which  now  lay  before  us.  Considering  the  nev£ 
which  supplies  it,  it  appeared  to  me  that  the  Viescher 
glacier  ought  to  discharge  as  much  ice  as  the  Aletsch ; 
but  this  is  an  error  due  to  the  extent  of  neve  which  is  here 
at  once  visible :  since  a  glance  at  the  map  of  this  portion 


110  THE   MOUNTAIN  ASSAILED.  [1858. 

of  the  Oberland  shows  at  once  the  great  superiority  of 
the  mountain  treasury  from  which  the  Aletsch  Glacier 
draws  support.  Still,  the  ice-field  before  us  was  a  most 
noble  one.  The  surrounding  mountains  were  of  impos- 
ing magnitude,  and  loaded  to  their  summits  with  snow. 
Down  the  sides  of  some  of  them  the  half-consolidated 
mass  fell  in  a  state  of  wild  fracture  and  confusion.  In 
some  cases  the  riven  masses  were  twisted  and  overturned, 
the  ledges  bent,  and  the  detached  blocks  piled  one  upon 
another  in  heaps  ;  while  in  other  cases  the  smooth  white 
mass  descended  from  crown  to  base  without  a  wrinkle. 
The  valley  now  below  us  was  gorged  by  the  frozen  ma- 
terial thus  incessantly  poured  into  it.  We  crossed  it,  and 
reached  the  base  of  the  Finsteraarhorn,  ascended  the 
mountain  a  little  way,  and  at  six  o'clock  paused  to  lighten 
our  burdens  and  to  refresh  ourselves. 

The  north  wind  had  freshened,  we  were  in  the  shade, 
and  the  cold  was  very  keen.  Placing  a  bottle  of  tea 
and  a  small  quantity  of  provisions  in  the  knapsack,  and 
a  few  figs  and  dried  prunes  in  our  pockets,  we  com- 
.menced  the  ascent.  The  Finsteraarhorn  sends  down  a 
number  of  cliffy  buttresses,  separated  from  each  other  by 
wide  couloirs  filled  with  ice  and  snow.  We  ascended 
one  of  these  buttresses  for  a  time,  treading  cautiously 
among  the  spiky  rocks ;  afterwards  we  went  along  the 
snow  at  the  edge  of  the  spine,  and  then  fairly  parted 
company  with  the  rock,  abandoning  ourselves  to  the  neve 
of  the  couloir.  The  latter  was  steep,  and  the  snow  was 
so  firm  that  steps  had  to  be  cut  in  it.  Once  I  paused 
upon  a  little  ledge,  which  gave  me  a  slight  footing,  and 
took  the  inclination.  The  slope  formed  an  angle  of  45° 
with  the  horizon  ;  and  across  it,  at  a  little  distance  be- 
low me,  a  gloomy  fissure  opened  its  jaws.  The  sun  now 
cleared  the  summits  which  had  before  cut  off  his  rays,  and 
burst  upon  us  with  great  power,  compelling  us  to  resort  to 


1858.]  THE   CREST   OF  ROCKS.  Ill 

our  veils  and  dark  spectacles.  Two  years  before,  Beimeu 
had  been  nearly  blinded  by  inflammation  brought  on  by 
the  glare  from  the  snow,  and  he  now  took  unusual  care  in 
protecting  his  eyes.  The  rocks  looking  more  practicable, 
we  again  made  towards  them,  and  clambered  among  them 
till  a  vertical  precipice,  which  proved  impossible  of  ascent, 
fronted  us.  Bennen  scanned  the  obstacle  closely  as  we 
slowly  approached  it,  and  finally  descended  to  the  snow, 
which  wound  at  a  steep  angle  round  its  base  :  on  this  the 
footing  appeared  to  me  to  be  singularly  insecure,  but  I 
marched  without  hesitation  or  anxiety  in  the  footsteps  of 
my  guide. 

We  ascended  the  rocks  once  more,  continued  along 
them  for  some  time,  and  then  deviated  to  the  couloir 
on  our  left.  This  snow-slope  is  much  dislocated  at  its 
lower  portion,  and  above  its  precipices  and  crevasses  our 
route  now  lay.  The  snow  was  smooth,  and  sufficiently 
firm  and  steep  to  render  the  cutting  of  steps  necessary. 
Bennen  took  the  lead :  to  make  each  step  he  swung  his 
mattock  once,  and  his  hindmost  foot  rose  exactly  at  the 
moment  the  mattock  descended ;  there  was  thus  a  kind 
of  rhythm  in  his  motion,  the  raising  of.  the  foot  keeping 
time  to  the  swing  of  the  implement.  In  this  manner  we 
proceeded  till  we  reached  the  base  of  the  rocky  pyramid 
which  caps  the  mountain. 

One  side  of  the  pyramid  had  been  sliced  off,  thus  drop- 
ping down  almost  a  sheer  precipice  for  some  thousands 
of  feet  to  the  Finsteraar  glacier.  A  wall  of  rock,  about 
10  or  15  feet  high,  runs  along  the  edge  of  the  moun- 
tain, and  this  sheltered  us  from  the  north  wind,  which 
surged  with  the  sound  of  waves  against  the  tremendous 
barrier  at  the  other  side.  "  Our  hardest  work  is  now 
before  us,"  said  my  guide.  Our  way  lay  up  the  steep 
and  splintered  rocks,  among  which  we  sought  out  the 
spikes  which  were  closely  enough  wedged  to  bear  our 


112  THE   SUMMIT   GAINED.  [1858. 

weight.  Each  had  to  trust  to  himself,  and  I  fulfilled  to 
the  letter  my  engagement  with  Beimen  to  ask  no  help. 
My  boiling-water  apparatus  and  telescope  were  on  my 
back,  much  to  my  annoyance,  as  the  former  was  heavy, 
and  sometimes  swung  awkwardly  round  as  I  twisted  my- 
self among  the  cliffs.  Bennen  offered  to  take  it,  but  he 
had  his  own  share  to  carry,  and  I  was  resolved  to  bear 
mine.  Sometimes  the  rocks  alternated  with  spaces  of  ice 
and  snow,  which  we  were  at  intervals  compelled  to  cross  ; 
sometimes,  when  the  slope  was  pure  ice  and  very  steep, 
we  were  compelled  to  retreat  to  the  highest  cliffs.  The 
wall  to  which  I  have  referred  had  given  way  in  some 
places,  and  through  the  gaps  thus  formed  the  wind  rushed 
with  a  loud,  wild,  wailing  sound.  Through  these  spaces 
I  could  see  the  entire  field  of  Agassiz's  observations ;  the 
junction  of  the  Lauteraar  and  Finsteraar  glaciers  at  the 
Abschwung,  the  medial  moraine  between  them,  on  which 
stood  the  Hotel  des  Neufchatelois,  and  the  pavilion  built 
by  M.  Dolfuss,  in  which  Huxley  and  myself  had  found 
shelter  two  years  before.  Bennen  was  evidently  anxious 
to  reach  the  summit,  and  recommended  all  observations 
to  be  postponed  until  after  our  success  had  been  assured. 
I  agreed  to  this,  and  kept  close  at  his  heels.  Strong  as 
he  was,  he  sometimes  paused,  laid  his  head  upon  his 
mattock,  and  panted  like  a  chased  deer.  He  complained 
of  fearful  thirst,  and  to  quench  it  we  had  only  my  bottle 
of  tea :  this  we  shared  loyally,  my  guide  praising  its  vir- 
tues, as  well  he  might.  Still  the  summit  loomed  above 
us ;  still  the  angry  swell  of  the  north  wind,  beating 
against  the  torn  battlements  of  the  mountain,  made  wild 
music.  Upward,  however,  we  strained  :  and  at  last,  on 
gaining  the  crest  of  a  rock,  Bennen  exclaimed,  in  a  jubi- 
lant voice,  "  Die  hochste  Spitze!"  -the  highest  point. 
In  a  moment  I  was  at  his  side,  and  saw  the  summit  with- 
in a  few  paces  of  us.  A  minute  or  two  placed  us  upon 


1858.]  THERMOMETER  PLACED.  118 

the  topmost  pinnacle,  with  the  blue  dome  of  heaven 
above  us,  and  a  world  of  mountains,  clouds,  and  glaciers 
beneath. 

A  notion  is  entertained  by  many  of  the  guides,  that  if 
you  go  to  sleep  at  the  summit  of  any  of  the  highest  moun- 
tains, you  will 

"  Sleep  the  sleep  that  knows  no  waking." 

Bennen  did  not  appear  to  entertain  this  superstition  ;  and 
before  starting  in  the  morning,  I  had  stipulated  for  ten 
minutes'  sleep  on  reaching  the  summit,  as  part  compensa- 
tion for  the  loss  of  the  night's  rest.  My  first  act,  after 
casting  a  glance  over  the  glorious  scene  beneath  us,  was 
to  take  advantage  of  this  agreement ;  so  I  lay  down  and 
had  five  minutes'  sleep,  from  which  I  rose  refreshed 
and  brisk.  The  sun  at  first  beat  down  upon  us  with 
intense  force,  and  I  exposed  my  thermometers ;  but  thin 
veils  of  vapour  soon  drew  themselves  before  the  sun,  and 
denser  mists  spread  over  the  valley  of  the  Rhone,  thus 
destroying  all  possibility  of  concert  between  Ramsay  and 
myself.  I  turned  therefore  to  my  boiling-water  apparatus, 
filled  it  with  snow,  melted  the  first  charge,  put  more  in, 
and  boiled  it ;  ascertaining  the  boiling  point  to  be  187° 
Fahrenheit.  On  a  sheltered  ledge,  about  two  or  three 
yards  south  of  the  highest  point,  I  placed  a  minimum- 
thermometer,  in  the  hope  that  it  would  enable  us  in 
future  years  to  record  the  lowest  winter  temperatures  at 
the  summit  of  the  mountain.* 

*  The  following  note  describes  the  single  observation  made  with  this 
thermometer.  Mr.  B.  informs  me  that  on  finding  the  instrument  Bennen 
swung  it  in  triumph  round  his  head.  I  fear,  therefore,  that  the  obser- 
vation gives  us  no  certain  information  regarding  the  minimum  winter 
temperature. 

"  St.  Nicholas,  1859,  Aug.  25. 

"  Sir, — On  Tuesday  last  (the  23rd  inst.)  a  party,  consisting  of  Messrs. 
B.,  II.,  R.  L.,  and  myself,  succeeded  in  reaching  the  summit  of  the  Finster 
Aarhorn  under  the  guidance  of  Bennen  aed  Melchior  Andre'.  We  made 

8 


114  SCENE  FROM  THE   SUMMIT.  [1858. 

It  is  difficult  to  convey  any  just  impression  of  the  scene 
from  the  summit  of  the  Finsteraarhorn  :  one  might,  it  is 
true,  arrange  the  visible  mountains  in  a  list,  stating  their 
heights  and  distances,  and  leaving  the  imagination  to  fur- 
nish them  with  peaks  and  pinnacles,  to  build  the  precipices, 
polish  the  snow,  rend  the  glaciers,  and  cap  the  highest 
summits  with  appropriate  clouds.  But  if  imagination  did 
its  best  in  this  way,  it  would  hardly  exceed  the  reality, 
and  would  certainly  omit  many  details  which  contribute 
to  the  grandeur  of  the  scene  itself.  The  various  shapes 
of  the  mountains,  some  grand,  some  beautiful,  bathed 
in  yellow  sunshine,  or  lying  black  and  riven  under  the 
frown  of  impervious  cumuli ;  the  pure  white  peaks,  cor- 
nices, bosses,  and  amphitheatres  ;  the  blue  ice  rifts,  the 

it  an  especial  object  to  observe  and  reset  the  minimum-thermometer  which 
you  left  there  last  year.  On  reaching  the  summit,  before  I  had  time  to 
stop  him,  Bennen  produced  the  instrument,  and  it  is  just  possible  that  in 
moving  it  he  may  have  altered  the  position  of  the  index.  However,  as  he 
held  the  instrument  horizontally,  and  did  not,  as  far  as  I  saw,  give  it  any 
sensible  jerk,  I  have  great  confidence  that  the  index  remained  unmoved. 

"  The  reading  of  the  index  was  — 32°  Cent. 

"A  portion  of  the  spirit  extending  over  about  10^°  (and  standing  be- 
tween 33°  and  43^°)  was  separated  from  the  rest,  but  there  appeared  to 
be  no  data  for  determining  when  the  separation  had  taken  place.  As  it 
appeared  desirable  to  unite  the  two  portions  of  spirit  before  again  setting  the 
index  to  record  the  cold  of  another  winter,  we  endeavoured  to  effect  this  by 
heating  the  bulb,  but  unfortunately,  just  as  we  were  expecting  to  see  them 
coalesce,  the  bulb  burst,  and  I  have  now  to  express  my  great  regret  that  my 
clumsiness  or  ignorance  of  the  proper  mode  of  setting  the  instrument  in 
order  should  have  interfered  with  the  continuance  of  observations  of  so 
much  interest.  The  remains  of  the  instrument,  together  with  a  note  of  the 
accident,  I  have  left  in  the  charge  of  Wellig,  the  landlord  of  the  hotel  on  the 
JEggischhorn. 

"  We  reached  the  summit  about  10.40  A.  M.  and  remained  there  till  noon  ; 
the  reading  of  a  pocket  thermometer  in  the  shade  was  41°  F. 

"  Should  there  be  any  further  details  connected  with  our  ascent  on  which 
you  would  like  to  have  information,  I  shall  be  happy  to  supply  them  to  the 
best  of  my  recollection  Meanwhile,  with  a  further  apology  for  my  clumsi- 
ness, I  beg  to  subscribe  mvself  yours  respectfully, 

"H." 

"  Professor  Tyndall." 


1858.]  "HAVE   NO   FEAK."  115 

stratified  snow-precipices,  the  glaciers  issuing  from  the 
hollows  of  the  eternal  hills,  and  stretching  like  frozen 
serpents  through  the  sinuous  valleys  ;  the  lower  cloud 
field  —  itself  an  empire  of  vaporous  hills  —  shining  with 
dazzling  whiteness,  while  here  and  there  grim  summits, 
brown  by  nature,  and  black  by  contrast,  pierce  through  it 
like  volcanic  islands  through  a  shining  sea ;  —  add  to  this 
the  consciousness  of  one's  position  which  clings  to  one 
unconsciously,  that  undercurrent  of  emotion  which  sur- 
rounds the  question  of  one's  personal  safety,  at  a  height 
of  more  than  14,000  feet  above  the  sea,  and  which  is  in- 
creased by  the  weird  strange  sound  of  the  wind  surging 
with  the  full  deep  boom  of  the  distant  sea  against  the 
precipice  behind,  or  rising  to  higher  cadences  as  it  forces 
itself  through  the  crannies  of  the  weatherworn  rocks,  — 
all  conspire  to  render  the  scene  from  the  Finsteraarhorn 
worthy  of  the  monarch  of  the  Bernese  Alps. 

My  guide  at  length  warned  me  that  we  must  be  mov- 
ing ;  repeating  the  warning  more  impressively  before  I 
attended  to  it.  We  packed  up,  and  as  we  stood  beside  each 
other  ready  to  march,  he  asked  me  whether  we  should  tie 
ourselves  together,  at  the  same  time  expressing  his  belief 
that  it  was  unnecessary.  Up  to  this  time  we  had  been 
separate,  and  the  thought  of  attaching  ourselves  had  not 
occurred  to  me  till  he  mentioned  it.  I  thought  it,  however, 
prudent  to  accept  the  suggestion,  and  so  we  united  our 
destinies  by  a  strong  rope.  "  Now,"  said  Bennen,  "  have  no 
fear ;  no  matter  how  you  throw  yourself,  I  will  hold  you." 
Afterwards,  on  another  perilous  summit,  I  repeated  this 
saying  of  Bennen's  to  a  strong  and  active  guide,  but  his  ob- 
servation was  that  it  was  a  hardy  untruth,  for  that  in  many 
places  Bennen  could  not  have  held  me.  Nevertheless  a  dar- 
ing word  strengthens  the  heart,  and,  though  I  felt  no  trace 
of  that  sentiment  which  Bennen  exhorted  me  to  banish, 
and  was  determined,  as  far  as  in  me  lay,  to  give  him  no 


116  DISCIPLINE.  [1858. 

opportunity  of  trying  his  strength  in  saving  me,  I  liked  the 
fearless  utterance  of  the  man,  and  sprang  cheerily  after 
him.  Our  descent  was  rapid,  apparently  reckless,  amid 
loose  spikes,  boulders,  and  vertical  prisms  of  rock,  where  a 

f  false  step  would  assuredly  have  been  attended  with  broken 
bones ;  but  the  consciousness  of  certainty  in  our  movements 
never  forsook  us,  and  proved  a  source  of  keen  enjoyment. 
The  senses  were  all  awake,  the  eye  clear,  the  heart  strong, 
the  limbs  steady,  yet  flexible,  with  power  of  recovery  in 
store,  and  ready  for  instant  action  should  the  footing  give 
way.  Such  is  the  discipline  which  a  perilous  ascent  imposes. 
We  finally  quitted  the  crest  of  rocks,  and  got  fairly  upon 
the  snow  once  more.  We  first  went  downwards  at  a  long 
swinging  trot.  The  sun  having  melted  the  crust  which 
we  were  compelled  to  cut  through  in  the  morning,  the  leg 
at  each  plunge  sank  deeply  into  the  snow  ;  but  this  sink- 
ing was  partly  in  the  direction  of  the  slope  of  the  moun- 
tain, and  hence  assisted  our  progresss.  Sometimes  the 
crust  was  hard  enough  to  enable  us  to  glide  upon  it  for 
long  distances  while  standing  erect ;  but  the  end  of  these 
glissades  was  always  a  plunge  and  tumble  in  the  deeper 
snow.  Once  upon  a  steep  hard  slope  Bennen's  footing- 
gave  way  ;  he  fell,  and  went  down  rapidly,  pulling  me  af- 
ter him.  I  fell  also,  but,  turning  quickly,  drove  the  spike 
of  my  hatchet  into  the  ice,  got  good  anchorage,  and  held 
both  fast ;  my  success  assuring  me  that  I  had  improved  as 
a  mountaineer  since  my  ascent  of  Mont  Blanc.  We  tum- 
bled so  often  in  the  soft  snow,  and  our  clothes  and  boots 
were  so  full  of  it,  that  we  thought  we  might  as  well  try 

^  the  sitting  posture  in  gliding  down.  We  did  so,  and 
descended  with  extraordinary  velocity,  being  checked  at 
intervals  by  a  bodily  immersion  in  the  softer  and  deeper 
snow.  I  was  usually  in  front  of  Bennen,  shooting  down 
with  the  speed  of  an  arrow,  and  feeling  the  check  of  the 
rope  when  the  rapidity  of  my  motion  exceeded  my  guide's 


1858.]  DESCENT  BY  GLISSADES.  117 

estimate  of  what  was  safe.  Sometimes  I  was  behind  him, 
and  darted  at  intervals  with  the  swiftness  of  an  avalanche 
right  upon  him ;  sometimes  in  the  same  transverse  line  with 
him,  with  the  full  length  of  the  rope  between  us ;  and  here 
I  found  its  check  unpleasant,  as  it  tended  to  make  me  roll 
over.  My  feet  were  usually  in  the  air,  and  it  was  only 
necessary  to  turn  them  right  or  left,  like  the  helm  of  a 
boat,  to  change  the  direction  of  motion  and  avoid  a  diffi- 
culty, while  a  vigorous  dig  of  leg  and  hatchet  into  the 
snow  was  sufficient  to  check  the  motion  and  bring  us  to 
rest.  Swiftly,  yet  cautiously,  we  glided  into  the  region  of 
crevasses,  where  we  at  last  rose,  quite  wet,  and  resumed 
our  walking,  until  we  reached  the  point  where  we  had  left 
our  wine  in  the  morning,  and  where  I  squeezed  the  water 
from  my  wet  clothes,  and  partially  dried  them  in  the  sun. 
We  had  left  some  things  at  the  cave  of  the  Faulberg, 
and  it  was  Bennen's  first  intention  to  return  that  way  and 
take  them  home  with  him.  Finding,  however,  that  we 
could  traverse  the  Viescher  glacier  almost  to  the  JEggisch- 
horn,  I  made  this  our  highway  homewards.  At  the  place 
where  we  entered  it,  and  for  an  hour  or  two  afterwards, 
the  glacier  was  cut  by  fissures,  for  the  most  part  covered 
with  snow.  We  had  packed  up  our  rope,  and  Bennen  ad- 
monished  me  to  tread  in  his  steps.  Three  or  four  times  he 
half  disappeared  in  the  concealed  fissures,  but  by  clutch- 
ing the  snow  he  rescued  himself  and  went  on  as  swiftly  as 
before.  Once  my  leg  sank,  and  the  ring  of  icicles  some 
fifty  feet  below  told  me  that  I  was  in  the  jaws  of  a  cre- 
vasse ;  my  guide  turned  sharply,  —  it  was  the  only  time 
that  I  had  seen  concern  on  his  countenance  :  — 

"  Golfs  Donner  !  Sie  haben  meine  Tritte  nicht  gefolgt." 

"  Doc/i ! "  vra&  my  only  reply,  and  we  went  on.     He 

scarcely  tried  the  snow  that  he  crossed,  as  from  its  form 

and  colour  he  could  in  most  cases  judge  of  its  condition. 

For  a  long  time  we  kept  at  the  left-hand  side  of  the 


118  THE  VIESCH  GLACIER.  [1858. 

glacier,  avoiding  the  fissures  which  were  now  permanently 
open.  We  came  upon  the  tracks  of  a  herd  of  chamois, 
which  had  clambered  from  the  glacier  up  the  sides  of  the 
Oberaarhorn,  and  afterwards  crossed  the  glacier  to  the 
right-hand  side,  my  guide  being  perfect  master  of  the 
ground.  His  eyes  went  in  advance  of  his  steps,  and  his 
judgment  was  formed  before  his  legs  moved.  The  glacier 
was  deeply  fissured,  but  there  was  no  swerving,  no  retreat- 
ing, no  turning  back  to  seek  more  practicable  routes ; 
each  stride  told,  and  every  stroke  of  the  axe  was  a  pro- 
fitable investment  of  labour. 

We  left  the  glacier  for  a  time,  and  proceeded  along  the 
mountain  side,  till  we  came  near  the  end  of  the  Trift 
glacier,  where  we  let  ourselves  down  an  awkward  face  of 
rock  along  the  track  of  a  little  cascade,  and  came  upon 
the  glacier  once  more.  Here  again  I  had  occasion  to 
admire  the  knowledge  and  promptness  of  my  guide.  The 
glacier,  as  is  well  known,  is  greatly  dislocated,  and  has 
once  or  twice  proved  a  prison  to  guides  and  travellers, 
but  Bennen  led  me  through  the  confusion  without  a  pause. 
We  were  sometimes  in  the  middle  of  the  glacier,  sometimes 
on  the, moraine,  and  sometimes  on  the  side  of  the  flanking 
mountain.  Towards  the  end  of  the  day  we  crossed  what 
seemed  to  be  the  consolidated  remains  of  a  great  ava- 
lanche ;  on  this  my  foot  slipped,  there  was  a  crevasse  at 
hand,  and  a  sudden  effort  was  necessary  to  save  me  from 
falling  into  it.  In  making  this  effort  the  spike  of  my 
axe  turned  uppermost,  and  the  palm  of  my  hand  came 
down  upon  it,  thus  inflicting  a  very  angry  wound.  We  were 
soon  upon  the  green  alp,  having  bidden  a  last  farewell  to 
the  ice.  Another  hour's  hard  walking  brought  us  to  our 
hotel.  No  one  seeing  us  crossing  the  alp  would  have  sup- 
posed that  we  had  laid  such  a  day's  work  behind  us  ;  the 
proximity  of  home  gave  vigour  to  our  strides,  and  our  pro- 
gress was  much  more  speedy  than  it  had  been  on  starting 


1858.]  A  ROTATING  ICEBERG.  119 

iii  the  morning.  I  was  affectionately  welcomed  by  Ram- 
say, had  a  warm  bath,  dined,  went  to  bed,  where  I  lay 
fast  locked  in  sleep  for  eight  hours,  and  rose  next  morn- 
ing as  fresh  and  vigorous  as  if  I  had  never  scaled  the 
Finsteraarhorn. 


(17.) 

ON  the  6th  of  August  there  was  a  long  fight  between 
mist  and  sunshine,  each  triumphing  by  turns,  till  at  length 
the  orb  gained  the  victory  and  cleansed  the  mountains 
from  every  trace  of  fog.  We  descended  to  the  Marjelen 
See,  and,  wishing  to  try  the  floating  power  of  its  icebergs, 
at  a  place  where  masses  sufficiently  large  approached 
near  to  the  shore,  I  put  aside  a  portion  of  my  clothes, 
and  retaining  my  boots  stepped  upon  the  floating  ice.  It 
bore  me  for  a  time,  and  I  hoped  eventually  to  be  able  to 
paddle  myself  over  the  water.  On  swerving  a  little, 
however,  from  the  position  in  which  I  first  stood,  the 
mass  turned  over  and  let  me  into  the  lake.  I  tried  a 
second  one,  which  served  me  in  the  same  manner ;  the 
water  was  too  cold  to  continue  the  attempt,  and  there 
was  also  some  risk  of  being  unpleasantly  ground  between 
the  opposing  surfaces  of  the  masses  of  ice.  A  very  large 
iceberg  which  had  been  detached  some  short  time  pre- 
viously from  the  glacier  lay  floating  at  some  distance 
from  us.  Suddenly  a  sound  like  that  of  a  waterfall  drew 
our  attention  towards  it.  We  saw  it  roll  over  with  the 
utmost  deliberation,  while  the  water  which  it  carried  along 
with  it  rushed  in  cataracts  down  its  sides.  Its  previous 
surface  was  white,  its  present  one  was  of  a  lovely  blue,  the 
submerged  crystal  having  now  come  to  the  air.  The 
summerset  of  this  iceberg  produced  a  commotion  all  over 
the  lake  ;  the  floating  masses  at  its  edge  clashed  together, 


120  END   OF   THE  ALETSCH  GLACIER.  [1858 

and  a  mellow  glucking  sound,  due  to  the  lapping  of  the 
undulations  against  the  frozen  masses,  continued  long 
afterwards. 

We  subsequently  spent  several  hours  upon  the  glacier ; 
and  on  this  day  I  noticed  for  the  first  time  a  contempo- 
raneous exhibition  of  bedding  and  structure  to  which  I  shall 
refer  at  another  place.  We  passed  finally  to  the  left  bank 
of  the  glacier,  at  some  distance  below  the  base  of  the 
^Eggischhorn,  and  traced  its  old  moraines  at  intervals  along 
the  flanks  of  the  bounding  mountain.  At  the  summit  of 
the  ridge  we  found  several  fine  old  roches  moutonnees,  on 
some  of  which  the  scratching?  of  a  glacier  long  departed 
were  well  preserved ;  and  from  the  direction  of  the 
scratchings  it  might  be  inferred  that  the  ice  moved  down 
the  mountain  towards  the  valley  of  the  Rhone.  A  plunge 
into  a  lonely  mountain  lake  ended  the  day's  excursion. 

On  the  7th  of  August  we  quitted  this  noble  station. 
Sending  our  guide  on  to  Yiesch  to  take  a  conveyance  and 
proceed  with  our  luggage  down  the  valley,  Ramsay  and 
myself  crossed  the  mountains  obliquely,  desiring  to  trace 
the  glacier  to  its  termination.  We  had  no  path,  but  it  was 
hardly  possible  to  go  astray.  We  crossed  spurs,  climbed  and 
descended  pleasant  mounds,  sometimes  with  the  soft  grass 
under  our  feet,  and  sometimes  knee-deep  in  rhododendrons. 
It  took  us  several  hours  to  reach  the  end  of  the  glacier, 
and  we  then  looked  down  upon  it  merely.  It  lay  couched 
like  a  reptile  in  a  wild  gorge,  as  if  it  had  split  the  moun- 
tain by  its  frozen  snout.  We  afterwards  descended  to 
Morill,  where  we  met  our  guide  and  driver ;  thence  down 
the  valley  to  Visp  ;  and  the  following  evening  saw  us 
lodged  at  the  Monte  Rosa  hotel  in  Zermatt. 

The  boiling-point  of  water  on  the  table  of  the  salle  a 
manger,  I  found  to  be  202.58°  Fahr. 

On  the  following  morning  I  proceeded  without  my  friend 
to  the  Gorner  glacier.  As  is  well  known,  the  end  of  this 


MEADOWS   INVADED   BY  ICE.  121 

glacier  has  been  steadily  advancing  for  several  years,  and 
when  I  saw  it,  the  meadow  in  front  of  it  was  partly 
shrivelled  up  by  its  irresistible  advance.  I  was  informed 
by  my  host  that  within  the  last  sixty  years  forty-four  cha- 
lets had  been  overturned  by  the  glacier,  the  ground  on 
which  they  stood  being  occupied  by  the  ice  ;  at  present 
there  are  others  for  which  a  similar  fate  seems  imminent. 
In  thus  advancing  the  glacier  merely  takes  up  ground 
which  belonged  to  it  in  former  ages,  for  the  rounded  rocks 
which  rise  out  of  the  adjacent  meadow  show  that  it  had 
once  passed  over  them. 

I  had  arranged  to  meet  Ramsay  this  morning  on  the 
road  to  the  RifFelberg.  The  meeting  took  place,  but  I 
then  learned  that  a  minute  or  two  after  my  departure  he 
had  received  intelligence  of  the  death  of  a  near  relative. 
Thus  was  our  joint  expedition  terminated,  for  he  resolved 
to  return  at  once  to  England.  At  my  solicitation  he  ac- 
companied me  to  the  Eiffel  hotel.  We  had  planned  an 
ascent  of  Monte  Rosa  together,  but  the  arrangement  thus 
broke  down,  and  I  was  consequently  thrown  upon  my 
own  resources.  Laueiier  had  never  made  the  ascent,  but 
he  nevertheless  felt  confident  that  we  should  accomplish 
it  together. 


122  THE  RIFFELBERG.  [1858. 

FIRST   ASCENT   OF   MONTE   ROSA,   1858. 
(18.) 

ON  Monday,  the  9th  of  August,  we  reached  the  Riffel, 
and,  by  good  fortune,  on  the  evening  of  the  same  day,  my 
guide's  brother,  the  well-known  Ulrich  Lauener,  also  arrived 
at  the  hotel  on  his  return  from  Monte  Rosa.  From  him  we 
obtained  all  the  information  possible  respecting  the  ascent, 
and  he  kindly  agreed  to  accompany  us  a  little  way  the 
next  morning,  to  put  iis  on  the  right  track.  At  three  A.M. 
the  door  of  my  bedroom  opened,  and  Christian  Lauener 
announced  to  me  that  the  weather  was  sufficiently  good  to 
justify  an  attempt.  The  stars  were  shining  overhead  ;  but 
Ulrich  afterwards  drew  our  attention  to  some  heavy  clouds 
which  clung  to  the  mountains  on  the  other  side  of  the 
valley  of  the  Visp  ;  remarking  that  the  weather  might 
continue  fair  throughout  the  day,  but  that  these  clouds 
were  ominous.  At  four  o'clock  we  were  on  our  way,  by 
which  time  a  gray  stratus  cloud  had  drawn  itself  across 
the  neck  of  the  Matterhorn,  and  soon  afterwards  another 
of  the  same  nature  encircled  his  waist.  We  proceeded 
past  the  Riffelhorn  to  the  ridge  above  the  Gorner  glacier, 
from  which  Monte  Rosa  was  visible  from  top  to  bottom, 
and  where  an  animated  conversation  in  Swiss  patois  com- 
menced. Ulrich  described  the  slopes,  passes,  and  preci- 
pices, which  were  to  guide  us ;  and  Christian  demanded 
explanations,  until  he  was  finally  able  to  declare  to  me 
that  his  knowledge  was  sufficient.  We  then  bade  Ulrich 
good-bye,  and  went  forward.  All  was  clear  about  Monte 
Rosa,  and  the  yellow  morning  light  shone  brightly  upon 
its  uppermost  snows.  Beside  the  Queen  of  the  Alps  was 
the  huge  mass  of  the  Lyskamm,  with  a  saddle  stretching 
from  the  one  to  the  other ;  next  to  the  Lyskamm  came 


1653.]  SOUNDS   ON  THE   GLACIER.  123 

two  white  rounded  mounds,  smooth  and  pure,  the  Twins 
Castor  and  Pollux,  and  further  to  the  right  again  the 
broad  brown  flank  of  the  Breithorn.  Behind  us  Mont 
Cervin  gathered  the  clouds  more  thickly  round  him,  until 
finally  his  grand  obelisk  was  totally  hidden.  We  went 
along  the  mountain-side  for  a  time,  and  then  descended 
to  the  glacier.  The  surface  was  hard  frozen,  and  the  ice 
crunched  loudly  under  our  feet.  There  was  a  hollowness 
and  volume  in  the  sound  which  require  explanation  ;  and 
this,  I  think,  is  furnished  by  the  remarks  of  Sir  John  Her- 
schel  on  those  hollow  sounds  at  the  Solfaterra,  near  Na- 
ples, from  which  travellers  have  inferred  the  existence  of 
cavities  within  the  mountain.  At  the  place  where  these 
sounds  are  heard  the  earth  is  friable,  and,  when  struck, 
the  concussion  is  reinforced  and  lengthened  by  the  partial 
echos  from  the  surfaces  of  the  fragments.  The  conditions 
for  a  similar  effect  exist  upon  the  glacier,  for  the  ice  is 
disintegrated  to  a  certain  depth,  and  from  the  innume- 
rable places  of  rupture  little  reverberations  are  sent, 
which  give  a  length  and  hollowness  to  the  sound  pro- 
duced by  the  crushing  of  the  fragments  on  the  surface. 

We  looked  to  the  sky  at  intervals,  and  once  a  meteor 
slid  across  it,  leaving  a  train  of  sparks  behind.  The  blue 
firmament,  from  which  the  stars  shone  down  so  brightly 
when  we  rose,  was  more  and  more  invaded  by  clouds, 
which  advanced  upon  us  from  our  rear,  while  before  us 
the  solemn  heights  of  Monte  Rosa  were  bathed  in  rich 
yellow  sunlight.  As  the  day  advanced  the  radiance  crept 
down  towards  the  valleys  ;  but  still  those  stealthy  clouds 
advanced  like  a  besieging  army,  taking  deliberate  posses- 
sion of  the  summits,  one  after  the  other,  while  grey  skir- 
mishers moved  through  the  air  above  us.  The  play  of 
light  and  shadow  upon  Monte  Rosa  was  at  times  beauti- 
ful, bars  of  gloom  and  zones  of  glory  shifting  and  alter- 
nating from  top  to  bottom  of  the  mountain. 


124  ADVANCE   OF   THE   CLOUDS.  [1853. 

At  five  o'clock  a  grey  cloud  alighted  on  the  shoulder  of 
the  Lyskamm,  which  had  hitherto  been  warmed  by  the 
lovely  yellow  light.  Soon  afterwards  we  reached  the  foot 
of  Monte  Rosa,  and  passed  from  the  glacier  to  a  slope  of 
rocks,  whose  rounded  forms  and  furrowed  surfaces  showed 
that  the  ice  of  former  ages  had  moved  over  them  ;  the 
granite  was  now  coated  with  lichens,  and  between  the 
bosses  where  mould  could  rest  were  patches  of  tender 
moss.  As  we  ascended,  a  peal  to  the  right  announced  the 
descent  of  an  avalanche  from  the  Twins  ;  it  came  heralded 
by  clouds  of  ice-dust,  which  resembled  the  sphered  masses 
of  condensed  vapour  which  issue  from  a  locomotive.  A 
gentle  snow-slope  brought  us  to  the  base  of  a  precipice 
of  brown  rocks,  round  which  we  wound ;  the  snow  was 
in  excellent  order,  and  the  chasms  were  so  firmly  bridged 
by  the  frozen  mass  that  no  caution  was  necessary  in  cross- 
ing them.  Surmounting  a  weathered  cliff  to  our  left,  we 
paused  upon  the  summit  to  look  upon  the  scene  around 
us.  The  snow  gliding  insensibly  from  the  mountains,  or 
discharged  in  avalanches  from  the  precipices  which  it  over 
hung,  filled  the  higher  valleys  with  pure  white  glaciers, 
which  were  rifted  and  broken  here  and  there,  exposing 
chasms  and  precipices  from  which  gleamed  the  delicate 
blue  of  the  half-formed  ice.  Sometimes,  however,  the 
neves  spread  over  wide  spaces  without  a  rupture  or  wrin- 
kle to  break  the  smoothness  of  the  superficial  snow.  The 
sky  was  now  for  the  most  part  overcast,  but  through  the 
residual  blue  spaces  the  sun  at  intervals  poured  light  over 
the  rounded  bosses  of  the  mountain. 

At  half-past  seven  o'clock  we  reached  another  precipice 
of  rock,  to  the  left  of  which  our  route  lay,  and  here 
Lauener  proposed  to  have  some  refreshment ;  after  which 
we  went  on  again.  The  clouds  spread  more  and  more, 
leaving  at  length  mere  specks  and  patches  of  blue 
between  them.  Passing  some  high  peaks,  formed  by 


MONTE   ROSA   CAPPED.  125 

the  dislocation  of  the  ice,  we  came  to  a  place  where  the 
neve  was  rent  by  crevasses,  on  the  walls  of  which  the 
I  stratification  due  to  successive  snow-falls  was  shown  with 
| great  beauty  and  definition.  Between  two  of  these  fissures 
jour  way  now  lay  :  the  wall  of  one  of  them  was  hollowed 
lout  longitudinally  midway  down,  thus  forming  a  roof 
|above  and  a  ledge  below,  and  from  roof  to  ledge  stretched 
a  railing  of  cylindrical  icicles,  as  if  intended  to  bolt  them 
(together.  A  cloud  now  for  the  first  time  touched  the 
[summit  of  Monte  Rosa,  and  sought  to  cling  to  it,  but  in 
a  minute  it  dispersed  in  shattered  fragments,  as  if  dashed 
to  pieces  for  its  presumption.  The  mountain  remained 
jfor  a  time  clear  and  triumphant,  but  the  triumph  was 
short-lived  :  like  suitors  that  will  not  be  repelled,  the 
jdusky  vapours  came  ;  repulse  after  repulse  took  place,  and 
jthe  sunlight  gushed  down  upon  the  heights,  but  it  was 
manifest  that  the  clouds  gained  ground  in  the  conflict. 

Until  about  a  quarter  past  nine  o'clock  our  work  was 
jmere  child's  play,  a  pleasant  morning  stroll  along  the 
iflanks  of  the  mountain  ;  but  steeper  slopes  now  rose 
jabove  us,  which  called  for  more  energy,  and  more  care  in 
the  fixing  of  the  feet.  Looked  at  from  below,  some  of 
jthese  slopes  appeared  precipitous ;  but  we  were  too  well 
acquainted  with  the  effect  of  fore-shortening  to  let  this 
daunt  us.  At  each  step  we  dug  our  batons  into  the  deep 
snow.  When  first  driven  in,  the  batons  *  dipped  from  us,  x 
but  were  brought,  as  we  walked  forward,  to  the  vertical, 
and  finally  beyond  it  at  the  other  side.  The  snow  was 
thus  forced  aside,  a  rubbing  of  the  staff  against  it,  and  of 
,the  snow-particles  against  each  other,  being  the  conse- 
iquence.  We  had  thus  perpetual  rupture  and  regelation  ; 
while  the  little  sounds  consequent  upon  rupture,  reinforced 
by  the  partial  echos  from  the  surfaces  of  the  granules, 

*  My  staff  was  always  the  haudle  of  an  axe  an  inch  or  two  longer  than 
an  ordinary  walking-stick. 


126  THE   "COMB"   OF   THE  MOUNTAIN.  [1858. 

were  blended  together  to  a  note  resembling  the  lowing  of 
cows.  Hitherto  I  had  paused  at  intervals  to  make  notes, 
or  to  take  an  angle ;  but  these  operations  now  ceased,  not 
from  want  of  time,  but  from  pure  dislike  ;  for  when  the 
eye  has  to  act  the  part  of  a  sentinel  who  feels  that  at  any 
moment  the  enemy  may  be  upon  him  ;  when  the  body 
must  be  balanced  with  precision,  and  legs  and  arms,  be- 
sides performing  actual  labour,  must  be  kept  in  readiness 
for  possible  contingencies  ;  above  all,  when  you  feel  that 
your  safety  depends  upon  yourself  alone,  and  that,  if  your 
footing  gives  way,  there  is  no  strong  arm  behind  ready  to 
be  thrown  between  you  and  destruction  ;  —  under  such 
circumstances  the  relish  for  writing  ceases,  and  you  are 
willing  to  hand  over  your  impressions  to  the  safe  keeping 
of  memory. 

From  the  vast  boss  which  constitutes  the  lower  portion 
of  Monte  Rosa,  cliffy  edges  run  upwards  to  the  summit. 
Were  the  snow  removed  from  these  we  should,  I  doubt 
not,  see  them  as  toothed  or  serrated  crags,  justifying  the 
term  "  kamm"  or  "  comb,"  applied  to  such  edges  by  tli€ 
Germans.  Our  way  now  lay  along  such  a  kamm,  the 
cliffs  of  which  had,  however,  caught  the  snow,  and  been 
completely  covered  by  it,  forming  an  edge  like  the  ridge 
of  a  house-roof,  which  sloped  steeply  upwards.  On  the 
Lyskamm  side  of  the  edge  there  was  no  footing,  and,  if  s 
human  body  fell  over  here,  it  would  probably  pass  througl 
a  vertical  space  of  some  thousands  of  feet,  falling  or  roll 
ing,  before  coming  to  rest.  On  the  other  side  the  snow 
slope  was  less  steep,  but  excessively  perilous-looking,  anc 
intersected  by  precipices  of  ice.  Dense  clouds  now  enve 
loped  us,  and  made  our  position  far  uglier  than  if  it  hac 
been  fairly  illuminated.  The  valley  below  us  was  one  vasi 
cauldron,  filled  with  precipitated  vapour,  which  came  seeth 
ing  at  times  up  the  sides  of  the  mountain.  Sometimes  this 
fog  would  partially  clear  away,  and  the  light  would  glean 


1858.]  ASCENT  ALONG  A   CORNICE.  127 

upwards  from  the  dislocated  glaciers.  My  guide  contin- 
ually admonished  me  to  make  my  footing  sure,  and  to  fix 
at  each  step  my  staff  firmly  in  the  consolidated  snow.  At 
one  place,  for  a  short  steep  ascent,  the  slope  became  hard 
ice,  and  our  position  a  very  ticklish  one.  We  hewed  our 
steps  as  we  moved  upwards,  but  were  soon  glad  to  deviate 
from  the  ice  to  a  position  scarcely  less  awkward.  The 
wind  had  so  acted  upon  the  snow  as  to  fold  it  over  the 
edge  of  the  kamm,  thus  causing  it  to  form  a  kind  of  cor- 
lice,  which  overhung  the  precipice  on  the  Lyskamm  side 
of  the  mountain.  This  cornice  now  bore  our  weight :  its 
snow  had  become  somewhat  firm,  but  it  was  yielding 
enough  to  permit  the  feet  to  sink  in  it  a  little  way,  and 
thus  secure  us  at  least  against  the  danger  of  slipping. 
Here  also  at  each  step  we  drove  our  batons  firmly  into 
:he  snow,  availing  ourselves  of  whatever  help  they  could 
render.  Once,  while  thus  securing  my  anchorage,  the 
landle  of  my  hatchet  went  right  through  the  cornice  on 
which  we  stood,  and,  on  withdrawing  it,  I  could  see^- 
hrough  the  aperture  into  the  cloud-crammed  gulf  below. 
We  continued  ascending  until  we  reached  a  rock  protrud- 
ng  from  the  snow,  and  here  we  halted  for  a  few  minutes. 
Lauener  looked  upwards  through  the  fog.  "  According 
:o  all  description,"  he  observed,  "  this  ought  to  be  the 
ast  kamm  of  the  mountain  ;  but  in  this  obscurity  we  can 
see  nothing."  Snow  began  to  fall,  and  we  recommenced 
our  journey,  quitting  the  rocks  and  climbing  again  along 
the  edge.  Another  hour  brought  us  to  a  crest  of  cliffs,  at 
which,  to  our  comfort,  the  kamm  appeared  to  cease,  and 
other  climbing  qualities  were  demanded  of  us. 

On  the  Lyskamm  side,  as  I  have  said,  rescue  would  be 
out  of  the  question,  should  the  climber  go  over  the  edge. 
On  the  other  side  of  the  edge  rescue  seemed  possible, 
though  the  slope,  as  stated  already,  was  most  dangerously 
steep.  I  now  asked  Lauener  what  he  would  have  done, 


128  "DIE  HOCHSTE   SPITZE."  [1858. 

supposing  my  footing  to  have  failed  on  the  latter  slope. 
He  did  not  seem  to  like  the  question,  but  said  that  he 
should  have  considered  well  for  a  moment  and  then  have 
sprung  after  me ;  but  he  exhorted  me  to  drive  all  such 
thoughts  away.  I  laughed  at  him,  and  this  did  more  to 
set  his  mind  at  rest  than  any  formal  profession  of  courage 
could  have  done.  We  were  now  among  rocks:  we  climbed" 
cliffs  and  descended  them,  and  advanced  sometimes  with 
our  feet  on  narrow  ledges,  holding  tightly  on  to  other 
ledges  by  our  fingers  ;  sometimes,  cautiously  balanced, 
we  moved  along  edges  of  rock  with  precipices  on  both 
sides.  Once,  in  getting  round  a  crag,  Lauener  shook  a 
book  from  his  pocket ;  it  was  arrested  by  a  rock  about 
sixty  or  eighty  feet  below  us.  He  wished  to  regain  it,  but 
I  offered  to  supply  its  place,  if  he  thought  the  descent  too 
dangerous.  He  said  he  would  make  the  trial,  and  parted 
from  me.  I  thought  it  useless  to  remain  idle.  A  cleft  was 
before  me,  through  which  I  must  pass  ;  so,  pressing  my 
knees  and  back  against  its  opposite  sides,  I  gradually  worked 
myself  to  the  top.  I  descended  the  other  face  of  the  rock, 
and  then,  through  a  second  ragged  fissure,  to  the  summit  of 
another  pinnacle.  The  highest  point  of  the  mountain  was 
now  at  hand,  separated  from  me  merely  by  a  short  saddle, 
carved  by  weathering  out  the  crest  of  the  mountain.  I  could 
hear  Lauener  clattering  after  me,  through  the  rocks  behind. 
I  dropped  down  upon  the  saddle,  crossed  it,  climbed  the  op- 
posite cliff,  and  "die  hochste  Spitze"  of  Monte  Rosa  was  won. 
Lauener  joined  me  immediately,  and  we  mutually  con- 
gratulated each  other  on  the  success  of  the  ascent.  Th 
residue  of  the  bread  and  meat  was  produced,  and  a  bottl 
of  tea  was  also  appealed  to.  Mixed  with  a  little  cognac 
Lauener  declared  that  he  had  never  tasted  anything  like  it 
Snow  fell  thickly  at  intervals,  and  the  obscurity  was  verj 
great ;  occasionally  this  would  lighten  and  permit  the  sun 
to  shed  a  ghastly  dilute  light  upon  us  through  the  gleaming 


1653.]  GLOOM  ON  THE   SUMMIT.  129 

vapour.  I  put  my  boiling-water  apparatus  in  order,  and 
fixed  it  in  a  corner  behind  a  ledge  ;  the  shelter  was,  how- 
ever, insufficient,  so  I  placed  my  hat  above  the  vessel. 
The  boiling-point  was  184°. 92  Fahr.,  the  ledge  on  which 
the  instrument  stood  being  5  feet  below  the  highest  point 
of  the  mountain. 

The  ascent  from  the  Eiffel  hotel  occupied  us  about 
seven  hours,  nearly  two  of  which  were  spent  upon  the 
kamm  and  crest.  Neither  of  us  felt  in  the  least  degree 
fatigued  ;  I,  indeed,  felt  so  fresh,  that  had  another  Monte 
Rosa  been  planted  on  the  first,  I  should  have  continued 
the  climb  without  hesitation,  and  with  strong  hopes  of 
reaching  the  top.  I  experienced  no  trace  of  mountain 
sickness,  lassitude,  shortness  of  breath,  heart-beat,  or 
headache  ;  nevertheless  the  summit  of  Monte  Rosa  is 
15,284  feet  high,  being  less  than  500  feet  lower  than 
Mont  Blanc.  It  is,  I  think,  perfectly  certain,  that  the 
rarefaction  of  the  air  at  this  height  is  not  sufficient  of 
itself  to  produce  the  symptoms  referred  to ;  physical  ex- 
ertion must  be  superadded. 

After  a  few  fitful  efforts  to  dispel  the  gloom,  the  sun 
resigned  the  dominion  to  the  dense  fog  and  the  descending 
snow,  which  now  prevented  our  seeing  more  than  15  or 
20  paces  in  any  direction.  The  temperature  of  the  crags 
at  the  summit,  which  had  been  shone  upon  by  the  un- 
clouded sun  during  the  earlier  portion  of  the  day,  was 
60°  Fahr. ;  hence  the  snow  melted  instantly  wherever  it 
came  in  contact  with  the  rock.  But  some  of  it  fell  upon 
my  felt  hat,  which  had  been  placed  to  shelter  the  boiling- 
water  apparatus,  and  this  presented  the  most  remarkable 
and  beautiful  appearance.  The  fall  of  snow  was  in  fact 
a  shower  of  frozen  flowers.  All  of  them  were  six-leaved ; 
some  of  the  leaves  threw  out  lateral  ribs  like  ferns,  some 
were  rounded,  others  arrowy  and  serrated,  some  were 
close,  others  reticulated,  but  there  was  no  deviation  from 
9 


130  "FROZEN  FLOWERS."  [1858. 

the  six-leaved  type.  Nature  seemed  determined  to  make 
us  some  compensation  for  the  loss  of  all  prospect,  and 
thus  showered  down  upon  us  those  lovely  blossoms  of  the 
frost ;  and  had  a  spirit  of  the  mountain  inquired  my 
choice,  the  view,  or  the  frozen  flowers,  I  should  have 
hesitated  before  giving  up  that  exquisite  vegetation.  It 
was  wonderful  to  think  of,  as  well  as  beautiful  to  behold. 
Let  us  imagine  the  eye  gifted  with  a  microscopic  power 
sufficient  to  enable  it  to  see  the  molecules  which  com- 
posed these  starry  crystals  ;  to  observe  the  solid  nucleus 
formed  and  floating  in  the  air  ;  to  see  it  drawing  towards 
it  its  allied  atoms,  and  these  arranging  themselves  as  if 
they  moved  to  music,  and  ended  by  rendering  that  music 
concrete.  Surely  such  an  exhibition  of  power,  such  an 
apparent  demonstration  of  a  resident  intelligence  in  what 
we  are  acustomed  to  call  "  brute  matter,"  would  appear 
perfectly  miraculous.  And  yet  the  reality  would,  if  we 
could  see  it,  transcend  the  fancy.  If  the  Houses  of  Par- 
liament were  built  up  by  the  forces  resident  in  their  own 
bricks  and  lithologic  blocks,  and  without  the  aid  of  hod- 
man or  mason,  there  would  be  nothing  intrinsically  more 
wonderful  in  the  process  than  in  the  molecular  architec- 
ture which  delighted  us  upon  the  summit  of  Monte  Rosa. 
Twice  or  thrice  had  my  guide  warned  me  that  we  must 
think  of  descending,  for  the  snow  continued  to  fall  heavily, 
and  the  loss  of  our  track  would  be  attended  with  imminent 
peril.  We  therefore  packed  up,  and  clambered  downward 
among  the  crags  of  the  summit.  We  soon  left  these  be- 
hind us,  and  as  we  stood  once  more  upon  the  kamm,  look- 
ing into  the  gloom  beneath,  an  avalanche  let  loose  from 
the  side  of  an  adjacent  mountain  shook  the  air  with  its 
thunder.  We  could  not  see  it,  could  form  no  estimate 
of  its  distance,  could  only  hear  its  roar,  which,  coining 
__  to  us  through  the  darkness,  had  an  undefinable  element 
of  horror  in  it.  Lauener  remarked,  "  I  never  hear  those 


1858.]  STARTLING  AVALANCHE.  131 

things  without  a  shudder;  the  memory  of  my  brother 
comes  back  to  me  at  the  same  time."  His  brother,  who 
was  the  best  climber  in  the  Oberland,  had  been  literally 
broken  to  fragments  by  an  avalanche  on  the  slopes  of  the 
Jungfrau. 

We  had  been  separate  coming  up,  each  having  trusted 
to  himself,  but  the  descent  was  more  perilous,  because  it 
is  more  difficult  to  fix  the  heel  of  the  boot  than  the  toe  se- 
curely in  the  ice.  Lauener  was  furnished  with  a  rope, 
which  he  now  tied  round  my  waist,  and  forming  a  noose 
at  the  other  end,  he  slipped  it  over  his  arm.  This  to  me 
was  a  new  mode  of  attachment.  Hitherto  my  guides  in 
dangerous  places  had  tied  the  ropes  round  their  waists 
also.  Simond  had  done  it  on  Mont  Blanc,  and  Bennen  on 
the  Finsteraarhorn,  proving  thus  their  willingness  to  share 
my  fate  whatever  that  might  be.  But  here  Lauener  had 
the  power  of  sending  me  adrift  at  any  moment,  should  his 
own  life  be  imperilled.  I  told  him  that  his  mode  of  attach- 
ment was  new  to  me,  but  he  assured  me  that  it  would 
give  him  more  power  in  case  of  accident.  I  did  not  see 
this  at  the  time  ;  but  neither  did  I  insist  on  his  attaching 
himself  in  the  usual  way.  It  could  neither  be  called 
anger  nor  pride,  but  a  warm  flush  ran  through  me  as  I 
remarked,  that  I  should  take  good  care  not  to  test  his 
power  of  holding  me.  I  believe  I  wronged  my  guide  by 
the  supposition  that  he  made  the  arrangement  with  refer- 
ence to  his  own  safety,  for  all  I  saw  of  him  afterwards 
proved  that  he  would  at  any  time  have  risked  his  life  to 
save  mine.  The  flush  however  did  me  good,  by  displacing 
every  trace  of  anxiety,  and  the  rope,  I  confess,  was  also  a 
source  of  some  comfort  to  me.  We  descended  the  kamm, 
I  going  first.  "  Secure  your  footing  before  you  move," 
was  my  guide's  constant  exhortation,  "  and  make  your 
staff  firm  at  each  step."  We  were  sometimes  quite  close 
upon  the  rim  of  the  kamm  on  the  Lyskamm  side,  and  we 


132  SPLENDID   BLUE   OF   THE   SNOW.  [1858..- 

also  followed  the  depressions  which  marked  our  track 
along  the  cornice.  This  I  now  tried  intentionally,  and 
drove  the  handle  of  my  axe  through  it  once  or  twice.  At 
two  places  in  descending  we  were  upon  the  solid  ice,  and 
these  were  some  of  the  steepest  portions  of  the  kamm. 
They  were  undoubtedly  perilous,  and  the  utmost  caution 
was  necessary  in  fixing  the  staff  and  securing  the  footing. 
These  however  once  passed,  we  felt  that  the  chief  danger 
was  over.  We  reached  the  termination  of  the  edge,  and ' 
although  the  snow  continued  to  fall  heavily,  and  obscure 
everything,  we  knew  that  our  progress  afterwards  was  se- 
cure. There  was  pleasure  in  this  feeling ;  it  was  an  agree- 
able variation  of  that  grim  mental  tension  to  which  I  had 
been  previously  wound  up,  but  which  in  itself  was  by  no 
means  disagreeable. 

I  have  already  noticed  the  colour  of  the  fresh  snow  upon 
the  summit  of  the  Stelvio  pass.  Since  I  observed  it  there 
it  has  been  my  custom  to  pay  some  attention  to  this  point 
at  all  great  elevations.  This  morning,  as  I  ascended  Monte 
Rosa,  I  often  examined  the  holes  made  in  the  snow  by  our 
batons,  but  the  light  which  issued  from  them  was  scarcely 
perceptibly  blue.  Now,  however,  a  deep  layer  of  fresh 
snow  overspread  the  mountain,  and  the  effect  was  magnifi- 
cent. Along  the  kamm  I  was  continually  surprised  and 
delighted  by  the  blue  gleams  which  issued  from  the  broken 
or  perforated  stratum  of  new  snow ;  each  hole  made  by 
the  staff  was  filled  with  a  light  as  pure,  and  nearly  as  deep, 
as  that  of  tho  unclouded  firmament.  (  When  we  reached 
the  bottom  of  the  kamm,  Lauener  came  to  the  front,  and 
tramped  before  me.  As  his  feet  rose  out  of  the  snow,  and 
shook  the  latter  off  in  fragments,  sudden  and  wonderful 
gleams  of  blue  light  flashed  from  them.  Doubtless  the 
blue  of  the  sky  has  much  to  do  with  mountain  colouring, 
but  in  the  present  instance  not  only  was  there  no  blue  sky, 
but  the  air  was  so  thick  with  fog  and  descending  snow- 


1858]  STIFLING  HEAT.  138 

flakes,  that  we  could  not  see  twenty  yards  in  advance  of 
us.  A  thick  fog,  which  wrapped  the  mountain  quite 
closely,  now  added  its  gloom  to  the  obscurity  caused  by 
the  falling  snow.  Before  we  reached  the  base  of  the 
mountain  the  fog  became  thin,  and  the  sun  shone  through 
it.  There  was  not  a  breath  of  air  stirring,  and,  though 
we  stood  ankle-deep  in  snow,  the  heat  surpassed  anything 
of  the  kind  I  had  ever  felt :  it  was  the  dead  suifocating 
warmth  of  the  interior  of  an  oven,  which  encompassed  us 
on  all  sides,  and  from  which  there  seemed  no  escape. 
Our  own  motion  through  the  air,  however,  cooled  us  con- 
siderably. We  found  the  snow-bridges  softer  than  in  the 
morning,  and  consequently  needing  more  caution  ;  but 
we  encountered  no  real  difficulty  among  them.  Indeed, 
it  is  amusing  to  observe  the  indifference  with  which  a 
snow-roof  is  often  broken  through,  and  a  traveller  im- 
mersed to  the  waist  in  the  jaws  of  a  fissure.  The  effort 
at  recovery  is  instantaneous  :  half  instinctively  hands  and 
knees  are  driven  into  the  snow,  and  rescue  is  immediate. 
Fair  glacier  work  was  now  before  us;  after  which  we 
reached  the  opposite  mountain  slope,  which  we  ascended, 
and  then  went  down  the  flank  of  the  Biffelberg  to  our  ho- 
tel. The  excursion  occupied  us  eleven  and  a  half  hours. 


(19.) 

ON  the  afternoon  of  the  llth  I  made  an  attempt  alone  to 
ascend  the  Riffelhorn,  and  attained  a  considerable  height; 
but  I  attacked  it  from  the  wrong  side,  and  the  fading 
light  forced  me  to  retreat.  I  found  some  agreeable  people 
at  the  hotel  on  my  return.  One  clergyman  especially, 
with  a  clear  complexion,  good  digestion,  and  bad  lungs  — 
of  free,  hearty,  and  genial  manner  —  made  himself  ex- 
tremely pleasant  to  us  all.  He  appeared  to  bubble  over 


134  A  DIFFICULT  DESCENT.  [1858. 

with  enjoyment,  and  with  him  and  others  on  the  morning 
of  the  13th  I  walked  to  the  Gorner  Grat,  as  it  lay  on  the 
way  to  my  work.  We  had  a  glorious  prospect  from  the 
summit:  indeed,  the  assemblage  of  mountains,  snow,  and 
ice  here  within  view  is  perhaps  without  a  rival  in  the 
world.*  I  shouldered  my  axe,  and  saying  "  Good-bye  " 
moved  away  from  my  companions. 

"  Are  you  going  ?  "  exclaimed  the  clergyman.  "  Give 
me  one  grasp  of  your  hand  before  we  part." 

This  was  the  signal  for  a  grasp  all  round ;  and  the 
hearty  human  kindness  which  thus  showed  itself  contrib- 
uted that  day  to  make  my  work  pleasant  to  me. 

We  proceeded  along  the  ridge  of  the  Rothe  Kiinim  to 
a  point  which  commanded  a  fine  view  of  the  glacier.  The 
ice  had  been  over  these  heights  in  ages  past,  for,  although 
lichens  covered  the  surfaces  of  the  old  rocks,  they  did  not 
disguise  the  grooves  and  scratchings.  The  surface  of  the 
glacier  was  now  about  a  thousand  feet  below  us,  and  this 
it  was  our  desire  to  attain.  To  reach  it  we  had  to  descend 
a  succession  of  precipices,  which  in  general  were  weathered 
and  rugged,  but  here  and  there,  where  the  rock  was 
durable,  were  fluted  and  grooved.  Once  or  twice  indeed 
we  had  nothing  to  cling  to  but  the  little  ridges  thus 
formed.  We  had  to  squeeze  ourselves  through  narrow 
tr—  fissures,  and  often  to  get  round  overhanging  ledges,  where 
our  main  trust  was  in  our  feet,  bat  where  these  had  only 
ledges  an  inch  or  so  in  width  to  rest  upon.  These  cases 
were  to  me  the  most  unpleasant  of  all,  for  they  compelled 
the  arms  to  take  a  position  which,  if  the  footing  gave  way, 
would  necessitate  a  wrench,  for  which  I  entertain  consider- 
able abhorrence.  We  came  at  length  to  a  gorge  by  which 
the  mountain  is  rent  from  top  to  bottom,  and  into  which 
we  endeavoured  to  descend.  We  worked  along  its  rim  for 

*  In  1858  Mr.  E.  W.  Cooke  made  a  pencil-sketch  of  this  splendid  pano- 
rama, which  is  the  best  and  truest  that  I  have  yet  seen. 


1858.]  SINGULAK  ICE-CAVE.  135 

a  time,  but  found  its  smooth  faces  too  deep.  We  retreated ; 
Lauener  struck  into  another  track,  and  while  he  tested 
it  I  sat  down  near  some  grass  tufts,  which  flourished  on 
one  of  the  ledges,  and  found  the  temperature  to  be  as 
follows :  — 

Temperature  of  rock         .         .  42°  C. 

Of  air  an  inch  above  the  rock       .  32 

Of  air  a  foot  from  rock     .         .  22 

Of  grass 25 

The  first  of  these  numbers  does  not  fairly  represent  the 
temperature  of  the  rock,  as  the  thermometer  could  be  in 
contact  with  it  only  at  one  side  at  a  time.  It  was  differ- 
ences such  as  these  between  grass  and  stone,  producing  a 
mixed  atmosphere  of  different  densities,  that  weakened  the 
sound  of  the  falls  of  the  Orinoco,  as  observed  and  explained 
by  Humboldt. 

By  a  process  of  "  trial  and  error  "  we  at  length  reached 
the  ice,  after  two  hours  had  been  spent  in  the  effort  to 
disentangle  ourselves  from  the  crags.  The  glacier  is 
forcibly  thrust  at  this  place  against  the  projecting  base 
of  the  mountain,  and  the  structure  of  the  ice  corre- 
spondingly developed.  Crevasses  also  intersect  the  ice, 
and  the  blue  veins  cross  them  at  right  angles.  I  as- 
cended the  glacier  to  -a  region  where  the  ice  was  com- 
pressed and  greatly  contorted,  and  thought  that  in  some 
cases  I  could  see  the  veins  crossing  the  lines  of  stratifi- 
cation. Once  my  guide  drew  my  attention  to  what  he 
called  "  ein  sonderbares  Loch."  On  one  of  the  slopes  an 
archway  was  formed  which  appeared  to  lead  into  the  body 
of  the  glacier.  We  entered  it,  and  explored  the  cavern  to 
its  end.  The  walls  were  of  transparent  blue  ice,  singularly 
free  from  air-bubbles  ;  but  where  the  roof  of  the  cavern 
was  thin  enough  to  allow  the  sun  to  shine  feebly  through 
it,  the  transmitted  light  was  of  a  pink  colour.  My  guide 


136  STRUCTURE  AND   STRATA.  [1858. 

expressed  himself  surprised  at  das  "  rothliche  Schein."  At 
one  place  a  plate  of  ice  had  been  placed  like  a  ceiling 
across  the  cavern  ;  but  owing  to  lateral  squeezing  it  had 
been  broken  so  as  to  form  a  V .  I  found  some  air-bubbles 
in  this  ice,  and  in  all  cases  they  were  associated  with 
blebs  of  water.  A  portion  of  the  "  ceiling,"  indeed,  was 
very  full  of  bubbles,  and  was  at  some  places  reduced,  by 
internal  liquefaction,  to  a  mere  skeleton  of  ice,  with  water- 
cells  between  its  walls. 

High  up  the  glacier  (towards  the  old  Weissthor)  the 
horizontal  stratification  is  everywhere  beautifully  shown. 
I  drew  my  guide's  attention  to  it,  and  he  made  the  re- 
mark that  the  perfection  of  the  lower  ice  was  due  to  the 
pressure  of  the  layers  above  it.  "  The  snow  by  degrees 
compressed  itself  to  glacier."  As  we  approached  one  of 
the  tributaries  on  the  Monte  Rosa  side,  where  great  pres- 
sure came  into  play,  the  stratification  appeared  to  yield 
and  the  true  structure  to  cross  it  at  those  places  where  it 
had  yielded  most.  As  the  place  of  greatest  pressure  was 
approached,  the  bedding  disappeared  more  and  more,  and 
a  clear  vertical  structure  was  finally  revealed. 


1858.]  GENERATION  OF  CLOUDS.  137 


THE    GORNER   GRAT   AND   THE    RIFFELHORN. 
MAGNETIC   PHENOMENA. 

(20.) 

AT  an  early  hour  on  Saturday,  the  14th  of  August,  I 
heard  the  servant  exclaim,  "  Das  Wetter  ist  ivunder- 
schon ;  "  which  good  news  caused  me  to  spring  from  my 
bed  and  prepare  to  meet  the  morn.  The  range  of  sum- 
mits at  the  opposite  side  of  the  valley  of  St.  Nicholas  was 
at  first  quite  clear,  but  as  the  sun  ascended  light  cumuli 
formed  round  them,  increasing  in  density  up  to  a  certain 
point ;  below  these  clouds  the  air  of  the  valley  was  trans- 
parent ;  above  them  the  air  of  heaven  was  still  more  so  ; 
and  thus  they  swung  midway  between  heaven  and  earth, 
ranging  themselves  in  a  level  line  along  the  necks  of  the 
mountains. 

It  might  be  supposed  that  the  presence  of  the  sun 
heating  the  air  would  tend  to  keep  it  more  transparent, 
by  increasing  its  capacity  to  dissolve  all  visible  cloud  ; 
and  this  indeed  is  the  true  action  of  the  sun.  But  it  is 
not  the  only  action.  His  rays,  as  he  climbed  the  eastern 
heaven,  shot  more  and  more  deeply  into  the  valley  of 
St.  Nicholas,  the  moisture  of  which  rose  as  invisible 
vapour,  remaining  unseen  as  long  as  the  air  possessed 
sufficient  warmth  to  keep  it  in  the  vaporous  state.  High 
up,  however,  the  cold  crags,  which  had  lost  their  heat 
by  radiation  the  night  before,  acted  like  condensers  upon 
the  ascending  vapour,  and  caused  it  to  curdle  into  visible 
fog.  The  current,  however,  continued  ascensional,  and 
the  clouds  were  slowly  lifted  above  the  tallest  peaks, 
where  they  arranged  themselves  in  fantastic  forms,  shift- 
ing and  changing  shape  as  they  gradually  melted  away. 


138  THE  ROCKS  WARMED.  [1858. 

One  peak  stood  like  a  field-officer  with  his  cap  raised 
above  his  head,  others  sent  straggling  cloud-balloons  up- 
wards ;  but  on  watching  these  outlyers  they  were  grad- 
ually seen  to  disappear.  At  first  they  shone  like  snow  in 
the  sunlight,  but  as  they  became  more  attenuated  they 
changed  colour,  passing  through  a  dull  red  to  a  dusky 
purple  hue,  until  finally  they  left  no  trace  of  their  ex- 
istence. 

As  the  day  advanced,  warming  the  rocks,  the  clouds 
wholly  disappeared,  and  a  hyaline  air  formed  the  setting 
of  both  glaciers  and  mountains.  I  climbed  to  the  Gorner 
Grat  to  obtain  a  general  view  of  the  surrounding  scene. 
Looking  towards  the  origin  of  the  Gorner  glacier  the  view 
was  bounded  by  a  wide  col,  upon  which  stood  two  lovely 
rounded  eminences  enamelled  with  snow  of  perfect  purity. 
They  shone  like  burnished  silver  in  the  sunlight,  as  if 
their  surfaces  had  been  melted  and  recongealed  to  frosted 
mirrors  from  which  the  rays  were  flung.  To  the  right 
of  these  were  the  bounding  crags  of  Monte  Rosa,  and 
then  the  body  of  the  mountain  itself,  with  its  crest  of 
crag  and  coat  of  snows.  To  the  right  of  Monte  Rosa, 
and  almost  rivalling  it  in  height,  was  the  vast  mass  of 
the  Lyskamm,  a  rough  and  craggy  mountain,  to  whose 
ledges  clings  the  snow  which  cannot  grasp  its  steeper 
walls,  sometimes  leaning  over  them  in  impending  preci- 
pices, which  often  break,  and  send  wild  avalanches  into 
the  space  below.  Between  the  Lyskamm  and  Monte 
Rosa  lies  a  large  wide  valley,  into  which  both  mountains 
pour  their  snows,  forming  there  the  Western  glacier  of 
Monte  Rosa,  —  a  noble  ice  stream,  which  from  its  mag- 
nitude and  permanence  deserves  to  impose  its  name  upon 
the  trunk  glacier.  It  extends  downwards  from  the  col 
which  unites  the  two  mountains  ;  riven  and  broken  at 
some  places,  but  at  others  stretching  white  and  pure  down 
to  its  snow-line,  where  the  true  glacier  emerges  from 


1858.]  SCENE  FROM  THE  CORNER  GRAT.  139 

the  neve.  From  the  rounded  shoulders  of  the  Twin  Castor 
a  glacier  descends,  at  first  white  and  shining,  then  sud- 
denly broken  into  faults,  fissures,  and  precipices,  which 
are  afterwards  repaired,  and  the  glacier  joins  that  of 
Monte  Rosa  before  the  junction  of  the  latter  with  the 
trunk  stream.  Next  came  a  boss  of  rock,  with  a  secondary 
glacier  clinging  to  it  as  if  plastered  over  it,  and  after  it  the 
Schwarze  glacier,  bounded  on  one  side  by  the  Breithorn, 
and  on  the  other  by  the  Twin  Pollux.  This  glacier  is  of 
considerable  magnitude.  Over  its  upper  portion  rise  the 
Twin  eminences,  pure  and  white ;  then  follows  a  smooth 
and  undulating  space,  after  passing  which  the  neve  is  torn 
up  into  a  collection  of  peaks  and  chasms ;  these,  however, 
are  mended  lower  down,  and  the  glacier  moves  smoothly 
and  calmly  to  meet  its  brothers  in  the  main  valley.  Next 
comes  the  Trifti  glacier,*  embraced  on  all  sides  by  the 
rocky  arms  of  the  Breithorn  ;  its  mass  is  not  very  great, 
but  it  descends  in  a  graceful  sweep,  and  exhibits  towards 
its  extremity  a  succession  of  beautiful  bands.  After- 
wards we  have  the  glacier  of  the  Petit  Mont  Cervin  and 
those  of  St.  Theodule,  which  latter  are  the  last  that  empty 
their  frozen  cargos  into  the  valley  of  the  Gorner.  All  the 
glaciers  here  mentioned  are  welded  together  to  a  common 
trunk  which  squeezes  itself  through  the  narrow  defile  at 
the  base  of  the  Riffelhorn.  Soon  afterwards  the  moraines 
become  confused,  the  glacier  drops  steeply  to  its  termina- 
tion, and  ploughs  up  the  meadows  in  front  of  it  with  its 
irresistible  share. 

In  a  line  with  the  Riffelhorn,  and  rising  over  the  latter 
so  high  as  to  make  it  almost  vanish  by  comparison,  was 
the  Titan  obelisk  of  the  Matterhorn,  from  the  base  of 
which  the  Furgge  glacier  struggles  downwards.  On  the 
other  side  are  the  Zmutt  glacier,  the  Schonbuhl,  and  the 

*  I  take  this  name  from  Studer's  map.  Sometimes,  however,  I  have 
called  it  the  "  Breithorn  glacier." 


140  COMPASS  AT  FAULT.  [1858. 

Hochwang,  from  the  Dent  Blanche ;  the  Gabelhorn  and 
Trift  glaciers,  from  the  summits  which  bear  those  names. 
Then  come  the  glaciers  of  the  Weisshorn.  Describing  a 
curve  still  farther  to  the  right,  we  alight  on  the  peaks 
of  the  Mischabel,  dark  and  craggy  precipices  from  this 
side,  though  from  the  ^Eggischhorn  they  appear  as  cones 
of  snow.  Sweeping  by  the  Alphubel,  the  Allaleinhorn, 
the  Rympfischorn,  and  Strahlhorn  —  all  of  them  majestic 
—  we  reach  the  pass  of  the  Weissthor,  and  the  Cima  di 
Jazzi.  This  completes  the  glorious  circuit  within  the  ob- 
server's view. 

I  placed  my  compass  upon  a  piece  of  rock  to  find  the 
bearing  of  the  Gorner  glacier,  and  was  startled  at  seeing 
the  sun  and  it  at  direct  variance.  What  the  sun  declared 
to  be  north,  the  needle  affirmed  to  be  south.  I  at  first 
supposed  that  the  maker  had  placed  the  S  where  the  N 
ought  to  be,  and  vice  versa.  On  shifting  my  position, 
however,  the  needle  shifted  also,  and  I  saw  immediately 
that  the  effect  was  due  to  the  rock  of  the  Grat.  Some- 
times one  end  of  the  needle  dipped  forcibly,  at  other  places 
it  whirled  suddenly  round,  indicating  an  entire  change  of 
polarity.  The  rock  was  evidently  to  be  regarded  as  an 
assemblage  of  magnets,  or  as  a  single  magnet  full  of 
"  consequent  points."  A  distance  of  transport  not  ex- 
ceeding an  inch  was,  in  some  cases,  sufficient  to  reverse 
the  position  of  the  needle.  I  held  the  needle  between 
the  two  sides  of  a  long  fissure  a  foot  wide.  The  needle 
set  along-  the  fissure  at  some  places,  while  at  others  it 
set  across  it.  Sometimes  a  little  jutting  knob  would 
attract  the  north  end  of  the  needle,  while  a  closely  ad- 
jacent little  knob  would  forcibly  repel  it,  and  attract 
the  south  end.  One  extremity  of  a  ledge  three  feet  long 
was  north  magnetic,  the  other  end  was  south  magnetic, 
while  a  neutral  point  existed  midway  between  both,  the 
ledge  having  therefore  the  exact  polar  arrangement  of  an 


1858.]  MAGNETISM  OF   ROCKS.  141 

ordinary  bar-magnet.  At  the  highest  point  of  the  rock 
the  action  appeared  to  be  most  intense,  but  I  also  found 
an  energetic  polarity  in  a  mass  at  some  distance  below  the 
summit. 

Remembering  that  Professor  Forbes  had  noticed  some 
peculiar  magnetic  effect  upon  the  Riffelhorn,  I  resolved  to 
ascend  it.  Descending  from  the  Grat,  we  mounted  the 
rocks  which  form  the  base  of  the  horn  ;  these  are  soft  and 
soapy  from  the  quantity  of  mica  which  they  contain  ;  the 
higher  rocks  of  the  horn  are,  however,  very  dense  and  hard. 
The  ascent  is  a  pleasant  bit  of  mountain  practice.  We 
climbed  the  walls  of  rock,  and  wound  round  the  ledges, 
seeking  the  assailable  points.  I  tried  the  magnetic  condi- 
tion of  the  rocks  as  we  ascended,  and  found  it  in  general 
feeble.  In  other  respects  the  Riffelhorn  is  a  most  remark- 
able mass.  The  ice  of  the  Gorner  glacier  of  former  ages, 
which  rose  hundreds,  perhaps  thousands  of  feet  above  its 
present  level,  encountered  the  horn  in  its  descent,  and 
was  split  by  the  latter,  a  diversion  of  the  ice  along  the 
sides  of  the  peak  being  the  consequence.  Portions  of  the 
vertical  walls  of  the  horn  are  polished  by  this  action  as 
if  they  had  come  from  the  hands  of  a  lapidary,  and  the 
scratchings  are  as  sharp  and  definite  as  if  drawn  by  points 
of  steel.  I  never  saw  scratchings  so  perfectly  preserved  : 
the  finest  lines  are  as  clear  as  the  deepest,  a  consequence 
of  the  great  density  and  durability  of  the  rock.  The 
latter  evidently  contains  a  good  deal  of  iron,  and  its  sur- 
face near  the  summit  is  of  the  rich  brown  red  due  to  the 
peroxide  of  the  metal.  When  we  fairly  got  among  the 
precipices  we  left  our  hatchets  behind  us,  trusting  subse- 
quently to  our  hands  and  feet  alone.  Squeezing,  creep- 
ing, clinging,  and  climbing,  in  due  time  we  found  our- 
selves upon  the  summit  of  the  horn. 

A  pile  of  stones  had  been  erected  near  the  point  where 
we  gained  the  top.  I  examined  the  stones  of  this  pile, 


142  ASCENT   OF   THE   RIFFELHORN.  [1858. 

and  found  them  strongly  polar.  The  surrounding  rocks 
also  showed  a  violent  action,  the  needle  oscillating  quickly, 
and  sometimes  twirling  swiftly  round  upon  a  slight  change 
of  position.  The  fragments  of  rock  scattered  about  were 
also  polar.  Long  ledges  shewed  north  magnetism  for  a 
considerable  length,  and  again  for  an  equal  length  south 
magnetism.  Two  parallel  masses  separated  from  each 
other  by  a  fissure,  showed  the  same  magnetic  distribution. 
While  I  was  engaged  at  one  end  of  the  horn,  Lauener 
wandered  to  the  other,  on  which  stood  two  or  three 
hommes  de  pierres.  He  was  about  disturbing  some  of 
the  stones,  when  a  yell  from  me  surprised  him.  In  fact, 
the  thought  had  occurred  to  me  that  the  magnetism  of 
the  horn  had  been  developed  by  lightning  striking  upon 
it,  and  my  desire  was  to  examine  those  points  which  were 
most  exposed  to  the  discharge  of  the  atmospheric  electri- 
city ;  hence  my  shout  to  my  guide  to  let  the  stones  alone. 
I  worked  towards  the  other  end  of  the  horn,  examining 
the  rocks  in  my  way.  Two  weathered  prominences,  which 
seemed  very  likely  recipients  of  the  lightning,  acted  vio- 
lently upon  the  needle.  I  sometimes  descended  a  little 
way,  and  found  that  among  the  rocks  below  the  summit 
the  action  was  greatly  enfeebled.  On  reaching  another 
very  prominent  point,  I  found  its  extremity  all  north 
polar,  but  at  a  little  distance  was  a  cluster  of  consequent 
points,  among  which  the  transport  of  a  few  inches  was 
sufficient  to  turn  the  needle  round  and  round. 

The  piles  of  stone  at  the  Zermatt  end  of  the  horn  did 
not  seem  so  strongly  polar  as  the  pile  at  the  other  end, 
which  was  higher ;  still  a  strong  polar  action  was  mani- 
fested at  many  points  of  the  surrounding  rocks.  Having 
completed  the  examination  of  the  summit,  I  descended 
the  horn,  and  examined  its  magnetic  condition  as  I  went 
along.  It  seemed  to  me  that  the  jutting  prominences 
always  exhibited  the  strongest  action.  I  do  not  indeed 


1858.]  MAGNETISM  OF  THE  HOEN.  143 

remember  any  case  in  which  a  strong  action  did  not  ex- 
hibit itself  at  the  ends  of  the  terraces  which  constitute 
the  horn.  In  all  cases,  however,  the  rock  acted  as  a 
number  of  magnets  huddled  confusedly  together,  and 
not  as  if  its  entire  mass  was  endowed  with  magnetism  of 
one  kind. 

On  the  evening  of  the  same  day  I  examined  the  lower 
spur  of  the  Riffelhorn.  Amid  its  fissures  and  gulleys  one 
feels  as  if  wandering  through  the  ruins  of  a  vast  castle 
or  fortification ;  the  precipices  are  so  like  walls,  and  the 
scratching  and  polishing  so  like  what  might  be  done  by 
the  hands  of  man.  I  found  evidences  of  strong  polar 
action  in  some  of  the  rocks  low  down.  In  the  same  con- 
tinuous mass  the  action  would  sometimes  exhibit  itself 
over  an  area  of  small  extent,  while  the  remainder  of  the 
rock  showed  no  appreciable  action.  Some  of  the  boulders 
cast  down  from  the  summit  exhibited  a  strong  and  varied 
polarity.  Fig.  8  is  a  sketch  of  one  of  these  ;  the  barbed 
end  of  each  arrow  repre- 
sents the  north  end  of  the 
needle,  which  assumed 
the  various  positions 
shown  in  the  figure.  Mid- 
way down  the  spur  I 
lighted  upon  a  trans- N 
verse  wall  of  rock,  which 
formed  in  earlier  ages 
the  boundary  of  a  lateral  outlet  of  the  Gorner  glacier. 
It  was  red  and  hard,  weathered  rough  at  some  places, 
and  polished  smooth  at  others.  The  lines  were  drawn 
finely  upon  it,  but  its  outer  surface  appeared  to  be  peel- 
ing off  like  a  crust ;  the  polished  layer  rested  upon  the 
rock  like  a  kind  of  enamel.  The  action  of  the  glacier 
appeared  to  resemble  that  of  the  break  of  a  locomotive 
upon  rails,  both  being  cases  of  exfoliation  brought  about 


144  THE  MAGNETIC  FORCE.  [1858. 

by  pressure  and  friction.  This  wall  measured  twenty- 
eight  yards  across,  and  one  end  of  it,  for  a  distance  of  ten 
or  twelve  yards,  was  all  north  polar  ;  the  other  end  for  a 
similar  distance  was  south  polar,  but  there  was  a  pair  of 
consequent  points  at  its  centre. 

To  meet  the  case  of  my  young  readers,  I  will  here  say 
a  few  words  about  the  magnetic  force.  The  common 
magnetic  needle  points  nearly  north  and  south ;  and  if  a 
bit  of  iron  be  brought  near  to  either  end  of  the  needle, 
they  will  mutually  attract  each  other.  A  piece  of  lead 
will  not  show  this  effect,  nor  will  copper,  gold,  nor  silver. 
Iron,  in  fact,  is  a  magnetic  metal,  which  the  others  are 
not.  It  is  to  be  particularly  observed,  that  the  bit  of  iron 
attracts  both  ends  of  the  needle  when  it  is  presented  to 
them  in  succession  ;  and  if  a  common  steel  sewing-needle 
be  substituted  for  the  iron,  it  will  be  seen  that  it  also  has 
the  power  of  attracting  both  ends  of  the  magnetic  needle. 
But  if  the  needle  be  rubbed  once  or  twice  along  one  end 
of  a  magnet,  it  will  be  found  that  one  of  its  ends  will 
afterwards  repel  a  certain  end  of  the  magnetic  needle  and 
attract  the  other.  By  rubbing  the  needle  on  the  magnet, 
we  thus  develop  both  attraction  and  repulsion,  and  this 
double  action  of  the  magnetic  force  is  called  its  polarity ; 
thus  the  steel  which  was  at  first  simply  magnetic,  is  now 
magnetic  and  polar. 

It  is  the  aim  of  persons  making  magnets,  that  each 
magnet  should  have  but  two  poles,  at  its  two  ends ;  but 
it  is  quite  easy  to  develop  in  the  same  piece  of  steel  sev- 
eral pairs  of  poles ;  and  if  the  magnetization  be  irregular, 
this  is  sometimes  done  when  we  wish  to  avoid  it.  These 
irregular  poles  are  called  consequent  points. 

Now  I  want  my  young  reader  to  understand  that  it  is 
not  only  because  the  rocks  of  the  Gorner  Grat  and  Riffel- 
horn  contain  iron,  that  they  exhibit  the  action  which  I 
have  described.  They  are  not  only  magnetic,  as  common 


1358.]  BEARINGS  FROM  THE  RIFFELHORN.  145 

iron  is,  but,  like  the  magnetized  steel  needle,  they  are 
magnetic  and  polar.  And  these  poles  are  irregularly  dis- 
tributed like  the  "  consequent  points  "  to  which  I  have 
referred,  and  this  is  the  reason  why  I  have  used  the  term. 
Professor  Forbes,  as  I  have  already  stated,  was  the  first 
to  notice  the  effect  of  the  Riffelhorn  upon  the  magnetic 
needle,  but  he  seems  to  have  supposed  that  the  entire 
mass  of  the  mountain  exercised  "  a  local  attraction  "  upon 
the  needle;  (upon  which  end  he  does  not  say).  To  en- 
able future  observers  to  allow  for  this  attraction,  he  took 
the  bearing  of  several  of  the  surrounding  mountains  from 
the  Riffelhorn  ;  but  it  is  very  probable  that  had  he 
changed  his  position  a  few  inches,  and  perfectly  certain 
had  he  changed  it  a  few  yards,  he  would  have  found  a  set  of 
bearings  totally  different  from  those  which  he  has  recorded. 
The  close  proximity  and  irregular  distribution  of  its  con- 
sequent points  would  prevent  the  Riffelhorn  from  exerting 
any  appreciable  influence  on  a  distant  needle,  as  in  this 
case  the  local  poles  would  effectually  neutralize  each  other. 


(21.) 

ON  the  morning  of  the  15th,  the  Riffelberg  was  swathed 
iii  a  dense  fog,  through  which  heavy  rain  showered  inces- 
santly. Towards  one  o'clock  the  continuity  of  the  gray 
mass  was  broken,  and  sky-gleams  of  the  deepest  blue 
were  seen  through  its  apertures ;  these  would  close  up 
again,  and  others  open  elsewhere,  as  if  the  fog  were 
fighting  for  existence  with  the  sun  behind  it.  The  sun, 
however,  triumphed,  the  mountains  came  more  and  more 
into  view,  and  finally  the  entire  air  was  swept  clear.  I 
went  up  to  the  Gorner  Grat  in  the  afternoon,  and  exam- 
ined more  closely  the  magnetism  of  its  rocks ;  here,  as  on 
the  Riffelhorn,  I  found  it  most  pronounced  at  the  jutting 
10 


146  MONT   CERVIN  AS   CLOUD-MAKER.  [1858. 

prominences  of  the  Grat.  Can  it  be  that  the  superior  ex- 
posure is  more  favourable  to  the  formation  of  the  magnetic 
oxide  of  iron  ?  I  secured  a  number  of  fragments,  which  I 
still  possess,  and  which  act  forcibly  upon  a  magnetic  needle. 
The  sun  was  near  the  western  horizon,  and  I  remained 
alone  upon  the  Grat  to  see  his  last  beams  illuminate  the 
mountains,  which,  with  one  exception,  were  without  a  trace 
of  cloud.  This  exception  was  the  Matterhorn,  the  appear- 
ance of  which  was  extremely  instructive.  The  obelisk 
appeared  to  be  divided  in  two  halves  by  a  vertical  line 
drawn  from  its  summit  half-way  down,  to  the  windward  of 
which  we  had  the  bare  cliffs  of  the  mountain  ;  and  to  the 
left  of  it  a  cloud  which  appeared  to  cling  tenaciously  to 
the  rocks.  In  reality,  however,  there  was  no  clinging ;  the 
condensed  vapour  incessantly  got  away,  but  it  was  ever 
renewed,  and  thus  a  river  of  cloud  had  been  sent  from 
the  mountain  over  the  valley  of  Aosta.  The  wind  in  fact 
blew  lightly  up  the  valley  of  St.  Nicholas  charged  with 
moisture,  and  when  the  air  that  held  it  rubbed  against  the 
cold  cone  of  the  Matterhorn  the  vapour  was  chilled  and 
precipitated  in  his  lee.  The  summit  seemed  to  smoke 
sometimes  like  a  burning  mountain ;  for  immediately  after 
its  generation,  the  fog  was  drawn  away  in  long  filaments 
by  the  wind.  As  the  sun  sank  lower  the  ruddiness  of  his 
light  augmented,  until  these  filaments  resembled  streamers 
of  flame.  The  sun  sank  deeper,  the  light  was  gradually 
withdrawn,  and  where  it  had  entirely  vanished  it  left  the 
mountain  like  a  desolate  old  man  whose 

"  hoary  hair 
Stream'd  like  a  meteor  in  the  troubled  air." 

For  a  moment  after  the  sun  had  disappeared  the  scene 
was  amazingly  grand.  The  distant  west  was  ruddy,  co- 
pious gray  smoke-wreaths  were  wafted  from  the  moun- 
tains, while  high  overhead,  in  an  atmospheric  region 
which  seemed  perfectly  motionless,  floated  a  broad  thin 


1858.]  CELLS  IN  THE  ICE.  147 

cloud,  dyed  with  the  richest  iridescences.  The  colours 
were  of  the  same  character  as  those  which  I  had  seen 
upon  the  Aletschorn,  being  due  to  interference,  and  in 
point  of  splendour  and  variety  far  exceeded  anything  ever 
produced  by  the  mere  coloured  light  of  the  setting  sun. 

On  the  16th  I  was  early  upon  the  glacier.  It  had  frozen 
hard  during  the  night,  and  the  partially  liberated  streams 
flowed,  in  many  cases,  over  their  own  ice.  I  took  some 
clear  plates  from  under  the  water,  and  found  in  them 
numerous  liquid  cells,  each  associated  with  an  air-bubble 
or  a  vacuous  spot.  The  most  common  shape  of  the  cells 
was  a  regular  hexagon,  but  there  were  all  forms  between 
the  perfect  hexagon  and  the  perfect  circle.  Many  cells 
had  also  crimped  borders,  intimating  that  their  primitive 
form  was  that  of  a  flower  with  six  leaves.  A  plate  taken 
from  ice  which  was  defended  from  the  sunbeams  by  the 
shadow  of  a  rock  had  no  such  cells ;  so  that  those  that  I 
observed  were  probably  due  to  solar  radiation. 

My  first  aim  was  to  examine  the  structure  of  the 
Gb'rnerhorn  glacier,  which  descends  the  breast  of  Monte 
Rosa  until  it  is  abruptly  cut  off  by  the  great  Western  gla- 
cier of  the  mountain.  Between  them  is  a  moraine  which 
is  at  once  terminal  as  regards  the  former,  and  lateral  as 
regards  the  latter.  The  ice  is  veined  vertically  along  the 
moraine,  the  direction  of  the  structure  being  parallel  to 
the  latter.  I  ascended  the  glacier,  and  found,  as  I  re- 
treated from  the  place  where  the  thrust  was  most  violent, 
that  the  structure  became  more  feeble.  From  the  glacier 
I  passed  to  the  rocks  called  aufder  Platte,  so  as  to  obtain 
a  general  view  of  its  terminal  portion.  The  gradual  per- 
fecting of  the  structure  as  the  region  of  pressure  was  ap- 
proached was  very  manifest :  the  ice  at  the  end  seemed  to 
wrinkle  up  in  obedience  to  the  pressure,  the  structural 
furrows,  from  being  scarcely  visible,  became  more  and 
more  decided,  and  the  lamination  underneath  correspond- 


148  STRUCTURE   OF  THE  ICE.  [1858. 

ingly  pronounced,  until  it  finally  attained  a  state  of  great 
perfection. 

I  now  quitted  the  rocks  and  walked  straight  across  the 
Western  glacier  of  Monte  Rosa  to  its  centre,  where  I 
found  the  structure  scarcely  visible.  I  next  faced  the  Gb'r- 
ner  Grat,  and  walked  down  the  glacier  towards  the  mo- 
raine which  divides  it  from  the  Gorner  glacier.  The 
mechanical  conditions  of  the  ice  here  are  quite  evident ; 
each  step  brought  me  to  a  place  of  greater  pressure,  and 
also  to  a  place  of  more  highly  developed  structure,  until 
finally,  near  to  the  moraine  itself,  and  running  parallel  to 
it,  a  magnificent  lamination  was  developed.  Here  the 
superficial  groovings  could  be  traced  to  great  distances, 
and  beside  the  moraine  were  boulders  poised  on  pedestals 
of  ice  through  which  the  blue  veins  ran.  At  some  places 
the  ice  had  been  weathered  into  Iamina3  not  more  than  a 
line  in  thickness. 

I  now  recrossed  the  Monte  Rosa  glacier  to  its  junction 
with  the  Schwartze  glacier,  which  descends  between  the 
Twins  and  Breithorn.  The  structure  of  the  Monte  Rosa 
glacier  is  here  far  less  pronounced  than  at  the  other 
side,  and  the  pressure  which  it  endures  is  also  manifestly 
less ;  the  structure  of  the  Schwartze  glacier  is  fairly  de- 
veloped, being  here  parallel  to  its  moraine.  The  cliffs  of 
the  Breithorn  are  much  exposed  to  weathering  action,  and 
boulders  are  copiously  showered  down  upon  the  adjacent 
ice.  Between  the  Schwartze  glacier  and  the  glacier  which 
descends  from  the  breast  of  the  Breithorn  itself  these 
blocks  ride  upon  a  spine  of  ice,  and  form  a  moraine  of 
grand  proportions.  From  it  a  fine  view  of  the  glacier  is 
attainable,  and  the  gradual  development  of  its  structure 
as  the  region  of  maximum  pressure  is  approached  is  very 
plain.  A  number  of  gracefully  curved  undulations  sweep 
across  the  Breithorn  glacier,  which  are  squeezed  more 
closely  together  as  the  moraine  is  approached.  All  the  gla- 


1858.]  TRIBUTARIES   EXPLORED.  149 

ciers  that  descend  from  the  flanking  mountains  of  the 
Gorner  valley  are  suddenly  turned  aside  where  they  meet 
the  great  trunk  stream,  and  are  reduced  by  the  pressure 
to  narrow  stripes  of  ice  separated  from  each  other  by 
parallel  moraines. 

I  ascended  the  Breithorn  glacier  to  the  base  of  an  ice- 
fall,  on  one  side  of  which  I  found  large  crumples  produced 
by  the  pressure,  the  veined  structure  being  developed  at 
right  angles  to  the  direction  of  the  latter.  No  such  struc- 
ture was  visible  above  this  place.  The  crumples  were 
cut  by  fissures,  perpendicular  to  which  the  blue  veins  ran. 
I  now  quitted  the  glacier,  and  clambered  up  the  adjacent 
alp,  from  which  a  fine  view  of  the  general  surface  was 
attainable.  As  in  the  case  of  the  Gornerhorn  glacier,  the 
gradual  perfecting  of  the  structure  was  very  manifest ; 
the  dirt,  which  first  irregularly  scattered  over  the  surface, 
gradually  assumed  a  striated  appearance,  and  became 
more  and  more  decided  as  the  moraine  was  approached. 
I  now  descended  from  the  alp,  and  endeavored  to  meas- 
ure some  of  the  undulations  ;  proceeding  afterwards  to 
the  junction  of  the  Breithorn  glacier  with  that  of  St. 
Theodule.  The  end  of  the  latter  appears  to  be  crumpled 
by  its  thrust  against  the  former,  and  the  moraine  between 
them,  instead  of  being  raised,  runs  along  a  hollow  which 
is  flanked  by  the  crumples  on  either  side.  The  Breithorn 
glacier  became  more  and  more  attenuated,  until  finally  it 
actually  vanished  under  its  own  moraines.  On  the  sides 
of  the  crevasses,  by  which  the  The'odule  glacier  is  here 
intersected,  I  thought  I  could  plainly  see  two  systems  of 
veins  cutting  each  other  at  an  angle  of  fifteen  or  twenty 
degrees.  Reaching  the  Gorner  glacier,  at  a  place  where 
its  dislocation  was  very  great,  I  proceeded  down  it  past 
the  Riffelhorn,  to  a  point  where  it  seemed  possible  to  scale 
the  opposite  mountain  wall.  Here  I  crossed  the  glacier, 
treading  with  the  utmost  caution  along  the  combs  of  ice, 


150  TEMPTATION.  [1858. 

and  winding  through  the  entanglement  of  crevasses  until 
the  spur  of  the  Kiffelhorn  was  reached  ;  this  I  climbed 
to  its  summit,  and  afterwards  crossed  the  Green  Alp  to 
our  hotel. 

The  foregoing  good  day's  work  was  rewarded  by  a 
sound  sleep  at  night.  The  tourists  were  called  in  succes- 
sion next  morning,  but  after  each  call  I  instantly  subsided 
into  deep  slumber,  and  thus  healthily  spaced  out  the 
interval  of  darkness.  Day  at  length  dawned  and  gradu- 
ally brightened.  I  looked  at  my  watch  and  found  it 
twenty  minutes  to  six.  My  guide  had  been  lent  to  a 
party  of  gentlemen  who  had  started  at  three  o'clock  for 
the  summit  of  Monte  Rosa,  and  he  had  left  with  me  a 
porter  who  undertook  to  conduct  me  to  one  of  the  adja- 
cent glaciers.  But  as  I  looked  from  my  window  the  un- 
speakable beauty  of  the  morning  filled  me  with  a  longing 
to  see  the  world  from  the  top  of  Monte  Rosa.  I  was  in 
exceedingly  good  condition,  —  could  I  not  reach  the  sum- 
mit alone  ?  Trained  and  indurated  as  I  had  been,  I  felt 
that  the  thing  was  possible;  at  all  events  I  could  try, 
without  attempting  anything  which  was  not  clearly  within 
my  power. 


1858.]  A   LIGHT  SCRIP.  151 

SECOND   ASCENT   OF   MONTE   ROSA,   1858. 
(22.) 

WHETHER  my  exercise  be  mental  or  bodily,  I  am  always 
most  vigorous  when  cool.  During  my  student  life  in 
Germany,  the  friends  who  visited  me  always  complained 
of  the  low  temperature  of  my  room,  and  here  among 
the  Alps  it  was  no  uncommon  thing  for  me  to  wander 
over  the  glaciers  from  morning  till  evening  in  my  shirt- 
sleeves. My  object  now  was  to  go  as  light  as  possible, 
and  hence  I  left  my  coat  and  neckcloth  behind  me.  trusting 
to  the  sun  and  my  own  motion  to  make  good  the  calorific 
waste.  After  breakfast  I  poured  what  remained  of  my  tea 
into  a  small  glass  bottle,  an  ordinary  demi-bouteille,  in 
fact ;  the  waiter  then  provided  me  with  a  ham-sandwich, 
and,  with  my  scrip  thus  frugally  furnished,  I  thought  the 
heights  of  Monte  Rosa  might  be  won.  I  had  neither 
brandy  nor  wine,  but  I  knew  the  immense  amount  of  me- 
chanical force  represented  by  four  ounces  of  bread  and 
ham,  and  I  therefore  feared  no  failure  from  lack  of  nutri- 
ment. Indeed,  I  am  inclined  to  think  that  both  guides 
and  travellers  often  impair  their  vigour  and  render  them- 
selves cowardly  and  apathetic  by  the  incessant  "  refresh- 
ing "  which  they  deem  it  necessary  to  indulge  in  on  such 
occasions. 

The  guide  whom  Lauener  intended  for  me  was  at  the 
door  ;  I  passed  him  and  desired  him  to  follow  me.  This 
he  at  first  refused  to  do,  as  he  did  not  recognise  me  in  my 
shirt-sleeves ;  but  his  companions  set  him  right,  and  he 
ran  after  me.  I  transferred  my  scrip  to  his  shoulders,  and 
led  the  way  upward.  Once  or  twice  he  insinuated  that  that 
was  not  the  way  to  the  Schwarze-see,  and  was  probably 
perplexed  by  my  inattention.  From  the  summit  of  the 


152  THE   GUIDE  EXPOSTULATES.  [1858. 

ridge  which  bounds  the  Gorner  glacier  the  whole  grand 
panorama  revealed  itself,  and  on  the  higher  slopes  of  Monte 
Rosa  —  so  high,  indeed,  as  to  put  all  hope  of  overtaking 
them,  or  even  coming  near  them,  out  of  the  question  —  a 
row  of  black  dots  revealed  the  company  which  had  started 
at  three  o'clock  from  the  hotel.  They  had  made  remark- 
ably good  use  of  their  time,  and  I  was  afterwards  informed 
that  the  cause  of  this  was  the  intense  cold,  which  compelled 
them  to  keep  up  the  proper  supply  of  heat  by  increased 
exertion.  I  descended  swiftly  to  the  glacier,  and  made  for 
the  base  of  Monte  Rosa,  my  guide  following  at  some  dis- 
tance behind  me.  One  of  the  streams,  produced  by  super- 
ficial melting,  had  cut  for  itself  a  deep  wide  channel  in  the 
ice  ;  it  was  not  too  wide  for  a  spring,  and  with  the  aid  of 
a  run  I  cleared  it  and  went  on.  Some  minutes  afterwards 
I  could  hear  the  voice  of  my  companion  exclaiming,  in  a 
tone  of  expostulation,  "  No,  no,  I  won't  follow  you  there." 
He  however  made  a  circuit,  and  crossed  the  stream ;  I 
waited  for  him  at  the  place  where  the  Monte  Rosa  glacier 
joins  the  rock,  "  aufder  Platte"  and  helped  him  down  the 
ice-slope.  At  the  summit  of  these  rocks  I  again  waited  for 
him.  He  approached  me  with  some  excitement  of  manner, 
and  said  that  it  now  appeared  plain  to  him  that  I  intended 
to  ascend  Monte  Rosa,  but  that  he  would  not  go  with  me. 
I  asked  him  to  accompany  me  to  the  summit  of  the  next 
cliff,  which  he  agreed  to  do  ;  and  I  found  him  of  some  ser- 
vice to  me.  He  discovered  the  faint  traces  of  the  party  in 
advance,  and,  from  his  greater  experience,  could  keep  them 
better  in  view  than  I  could.  We  lost  them,  however,  near 
the  base  of  the  cliff  at  which  we  aimed,  and  I  went  on, 
choosing  as  nearly  as  I  could  remember  the  route  followed 
by  Lauener  and  myself  a  week  previous,  while  my  guide 
took  another  route,  seeking  for  the  traces.  The  glacier 
here  is  crevassed,  and  I  was  among  the  fissures  some  dis- 
tance in  advance  of  my  companion.  Fear  was  manifestly 


1858.]  THE   GUIDE   HALTS.  153 

getting  the  better  of  him,  and  he  finally  stood  still,  ex- 
claiming, "  No  man  can  pass  there."  At  the  same 
moment  I  discovered  the  trace,  and  drew  his  attention 
to  it ;  he  approached  me  submissively,  said  that  I  was 
quite  right,  and  declared  his  willingness  to  go  on.  We 
climbed  the  cliff,  and  discovered  the  trace  in  the  snow 
above  it.  Here  I  transferred  the  scrip  and  telescope  to 
my  own  shoulders,  and  gave  my  companion  a  cheque  for 
five  francs.  He  returned,  and  I  went  on  alone. 

The  sun  and  heaven  were  glorious,  but  the  cold  was 
nevertheless  intense,  for  it  had  frozen  bitterly  the  night 
before.  The  mountain  seemed  more  noble  and  lovely 
than  when  I  had  last  ascended  it ;  and  as  1  climbed  the 
slopes,  crossed  the  shining  cols,  and  rounded  the  vast 
snow-bosses  of  the  mountain,  the  sense  of  being  alone 
lent  a  new  interest  to  the  glorious  scene.  I  followed  the 
track  of  those  who  preceded  me,  which  was  that  pursued 
by  Lauener  and  myself  a  week  previously.  Once  I  devi- 
ated from  it  to  obtain  a  glimpse  of  Italy  over  the  saddle 
which  stretches  from  Monte  Rosa  to  the  Lyskamm.  Deep 
below  me  was  the  valley,  with  its  huge  and  dislocated 
nevS,  and  the  slope  on  which  I  hung  was  just  sufficiently 
steep  to  keep  the  attention  aroused  without  creating  anx- 
iety. I  prefer  such  a  slope  to  one  on  which  the  thought 
of  danger  cannot  be  entertained.  I  become  more  weary 
upon  a  dead  level,  or  in  walking  up  such  a  valley  as  that, 
which  stretches  between  Visp  and  Zermatt,  than  on  a 
steep  mountain-side.  The  sense  of  weariness  is  often  no 
index  to  the  expenditure  of  muscular  force  :  the  muscles 
may  be  charged  with  force,  and,  if  the  nervous  excitant 
be  feeble,  the  strength  lies  dormant,  and  we  are  tired 
without  exertion.  But  the  thought  of  peril  keeps  the 
mind  awake,  and  spurs  the  muscles  into  action  ;  they 
move  with  alacrity  and  freedom,  and  the  time  passes 
swiftly  and  pleasantly. 


154  LEFT  ALONE.  [1858. 

Occupied  with  my  own  thoughts  as  I  ascended,  I  some- 
times unconsciously  went  too  quickly,  and  felt  the  effects 
of  the  exertion.  I  then  slackened  my  pace,  allowing  each 
limb  an  instant  of  repose  as  I  drew  it  out  of  the  snow, 
and  found  that  in  this  way  walking  became  rest.  This 
is  an  illustration  of  the  principle  which  runs  throughout 
nature,  —  to  accomplish  physical  changes,  time  is  neces- 
sary. Different  positions  of  the  limb  require  different 
molecular  arrangements  ;  and  to  pass  from  one  to  the 
other  requires  time.  By  lifting  the  leg  slowly  and  allow- 
ing it  to  fall  forward  by  its  own  gravity,  a  man  may  get/ 
on  steadily  for  several  hours,  while  a  very  slight  addition^ 
to  this  pace  may  speedily  exhaust  him.  Of  course  the 
normal  pace  differs  in  different  persons,  but  in  all  the 
power  of  endurance  may  be  vastly  augmented  by  the 
prudent  outlay  of  muscular  force. 

The  sun  had  long  shone  down  upon  me  with  intense 
fervour,  but  I  now  noticed  a  strange  modification  of  the 
light  upon  the  slopes  of  snow.  I  looked  upwards,  and 
saw  a  most  gorgeous  exhibition  of  interference-colours 
A  light  veil  of  clouds  had  drawn  itself  between  me  anc 
the  sun,  and  this  was  flooded  with  the  most  brilliant  dyes 
Orange,  red,  green,  blue  —  all  the  hues  produced  by  dif- 
fraction were  exhibited  in  the  utmost  splendour.  There 
seemed  a  tendency  to  form  circular  zones  of  colour  round 
the  sun,  but  the  clouds  were  not  sufficiently  uniform  to 
permit  of  this,  and  they  were  consequently  broken  into 
spaces,  each  steeped  with  the  colour  due  to  the  condition 
of  the  cloud  at  the  place.  Three  times  during  my  ascent 
similar  veils  drew  themselves  across  the  sun,  and  at  each  pas- 
sage the  splendid  phenomena  were  renewed.  As  I  reached 
the  middle  of  the  mountain  an  avalanche  was  let  loose  from 
the  -sides  of  the  Lyskamm;  the  thunder  drew  my  eyes 
to  the  place  :  I  saw  the  ice  move,  but  it  was  only  the  tail 
of  the  avalanche ;  still  the  volume  of  sound  told  me  that  it 


1858.]  GIDDINESS   ON   THE   KAMM.  155 

was  a  huge  one.  Suddenly  the  front  of  it  appeared  from 
behind  a  projecting  rock,  hurling  its  ice-masses  with  fury 
into  the  valley,  and  tossing  its  rounded  clouds  of  ice-dust 
high  into  the  atmosphere.  A  wild  long-drawn  sound, 
multiplied  by  echos,  now  descended  from  the  heights 
above  me.  It  struck  me  at  first  as  a  note  of  lamentation, 
and  I  thought  that  possibly  one  of  the  party  which  was 
now  near  the  summit  had  gone  over  the  precipice.  On 
listening  more  attentively  I  found  that  the  sound  shaped 
itself  into  an  English  "  hurrah  !  "  I  was  evidently  near- 
ing  the  party,  and  on  looking  upwards  I  could  see  them, 
nit  still  at  an  immense  height  above  me.  The  summit 
still  rose  before  them,  and  I  therefore  thought  the  cheer 
)reinature.  A  precipice  of  ice  was  now  in  front  of  me, 
around  which  I  wound  to  the  right,  and  in  a  few  minutes 
bund  myself  fairly  at  the  bottom  of  the  Kamm. 

I  paused  here  for  a  moment,  and  reflected  on  the  work 
)efore  me.  My  head  was  clear,  my  muscles  in  perfect 
;ondition,  and  I  felt  just  sufficient  fear  to  render  me  care- 
ul.  I  faced  the  Kamm,  and  went  up  slowly  but  surely, 
and  soon  heard  the  cheer  which  announced  the  arrival  of 
;he  party  at  the  summit  of  the  mountain.  It  was  a  wild, 
weird,  intermittent  sound,  swelling  or  falling  as  the  echos 
reinforced  or  enfeebled  it.  In  getting  through  the  rocks 
which  protrude  from  the  snow  at  the  base  of  the  last 
spur  of  the  mountain,  I  once  had  occasion  to  stoop  my 
head,  and,  on  suddenly  raising  it,  my  eyes  swam  as  they 
rested  on  the  unbroken  slope  of  snow  at  my  left.  The 
sensation  was  akin  to  giddiness,  but  I  believe  it  was  chiefly 
lue  to  the  absence  of  any  object  upon  the  snow  upon 
which  I  could  converge  the  axes  of  my  eyes.  Up  to  this 
Doint  I  had  eaten  nothing.  I  now  unloosed  my  scrip, 
md  had  two  mouthfuls  of  sandwich  and  nearly  the  whole 
)f  the  tea  that  remained.  I  found  here  that  my  load, 
ight  as  it  was,  impeded  me.  When  fine  balancing  is 


156  SCRIP  LEFT  BEHIND.  [1858. 

necessary,  the  presence  of  a  very  light  load,  to  which  one 
is  unaccustomed,  may  introduce  an  element  of  danger, 
and  for  this  reason  I  here  left  the  residue  of  my  tea  and 
sandwich  behind  me.  A  long  long  edge  was  now  in  front 
of  me,  sloping  steeply  upwards.  As  I  commenced  the 
ascent  of  this,  the  foremost  of  those  whose  cheer  had 
reached  me  from  the  summit  some  time  previously, 
appeared  upon  the  top  of  the  edge,  and  the  whole  party 
was  seen  immediately  afterwards  dangling  on  the  Kamm. 
We  mutually  approached  each  other.  Peter  Bohren,  a 
well-known  Oberland  guide,  came  first,  and  after  him 
came  the  gentleman  in  his  immediate  charge.  Then 
came  other  guides  with  other  gentlemen,  and  last  of  all 
my  guide,  Lauener,  with  his  strong  right  arm  round  the 
youngest  of.  the  party.  We  met  where  a  rock  protruded 
through  the  snow.  The  cold  smote  my  naked  throat 
bittely,  so  to  protect  it  I  borrowed  a  handkerchief  from 
Lauener,  bade  my  new  acquaintances  good  bye,  and  pro- 
ceeded upwards.  I  was  soon  at  the  place  where  the 
snow-ridge  joins  the  rocks  which  constitute  the  crest  of 
the  mountain ;  through  these  my  way  lay,  every  step  I 
took  augmenting  my  distance  from  all  life,  and  increasing 
my  sense  of  solitude.  I  went  up  arid  down  the  cliffs  as 
before,  round  ledges,  through  fissures,  along  edges  of  rock, 
over  the  last  deep  and  rugged  indentation,  and  up  the 
rocks  at  its  opposite  side,  to  the  summit. 

A  world  of  clouds  and  mountains  lay  beneath  m 
Switzerland,  with  its  pomp  of  summits,  was  clear  and 
grand ;  Italy  was  also  grand,  but  more  than  half  obscured. 
Dark  cumulus  and  dark  crag  vied  in  savagery,  while  al 
other  places  white  snows  and  white  clouds  held  equal 
rivalry.  The  scooped  valleys  of  Monte  Rosa  itself  were 
magnificent,  all  gleaming  in  the  bright  sunlight  —  tossed 
and  torn  at  intervals,  and  sending  from  their  rents  and 
walls  the  magical  blue  of  the  ice.  Ponderous  neves  lay 


1858.]  ALONE  ON  THE   SUMMIT.  157 

upon   the    mountains,   apparently   motionless,   but   sug- 
gesting   motion,  —  sluggish,   but    indicating    irresistible 
dynamic  energy,  which  moved  them  slowly  to  their  doom 
n  the  warmer  valleys  below.     I  thought  of  my  position  : 
t  was  the  first  time  that  a  man  had  stood  alone  upon 
hat  wild  peak,  and  were  the  imagination  let  loose  amid 
he  surrounding  agencies,  and  permitted  to  dwell  upon 
he  perils  which  separated  the  climber  from  his  kind,  I 
dare  say  curious  feelings  .might  have  been  engendered. 
But  I  was  prompt  to  quell  all  thoughts  which  might  lessen 
my  strength,  or  interfere  with  the  calm  application  of  it. 
Once  indeed  an  accident  made  me  shudder.    While  taking 
;he  cork  from  a  bottle  which  is  deposited  on  the  top,  and 
which  contains  the  names  of  those  who  have  ascended  the 
mountain,  my  axe  slipped  out  of  my  hand,  and  slid  some 
hirty  feet  away  from  me.    The  thought  of  losing  it  made 
iiy  flesh  creep,  for  without  it  descent  would  be  utterly 
mpossible.     I  regained  it,  and  looked  upon  it  with  an 
affection  which  might  be  bestowed  upon  a  living  thing, 
or  it  was  literally  my  staff  of  life  under  the  circum- 
stances.   One  look  more  over  the  cloud-capped  mountains 
of  Italy,  and  I  then  turned  my  back  upon  them,  and 
commenced  the  descent. 

The  brown  crags  seemed  to  look  at  me  with  a  kind  of 
riendly  recognition,  and,  with  a  surer  and  firmer  feeling 
;han  I  possessed  on  ascending,  I  swung  myself  from  crag 
;o  crag  and  from  ledge  to  ledge  with  a  velocity  which 
surprised  myself.  I  reached  the  summit  of  the  Kamm, 
and  saw  the  party  which  I  had  passed  an  hour  and  a  half 
oefore,  emerging  from  one  of  the  hollows  of  the  moun- 
tain ;  they  had  escaped  from  the  edge  which  now  lay  be- 
tween them  and  me.  The  thought  of  the  possible  loss  of 
nay  axe  at  the  summit  was  here  forcibly  revived,  for 
without  it  I  dared  not  take  a  single  step.  My  first  care 
to  anchor  it  firmly  in  the  snow,  so  as  to  enable  it 


158  THE  AXE   SLIPS.  [1858. 

to  bear  at  times  nearly  the  whole  weight  of  my  body. 
In  some  places,  however,  the  anchor  had  but  a  loose 
hold  ;  the  "  cornice  "  to  which  I  have  already  referred 
became  granular,  and  the  handle  of  the  axe  went  through 
it  up  to  the  head,  still,  however,  remaining  loose.  Some 
amount  of  trust  had  thus  to  be  withdrawn  from  the 
staff  and  placed  in  the  limbs.  A  curious  mixture  of  care- 
lessness and  anxiety  sometimes  fills  the  mind  on  such  oc- 
casions. I  often  caught  myself  humming  a  verse  of  a 
frivolous  song,  but  this  was  mechanical,  and  the  sub- 
stratum of  a  man's  feelings  under  such  circumstances  is 
real  earnestness.  The  precipice  to  my  left  was  a  continual 
preacher  of  caution,  and  the  slope  to  my  right  was  hardly 
less  impressive.  I  looked  down  the  former  but  rarely, 
and  sometimes  descended  for  a  considerable  time  without 
looking  beyond  my  own  footsteps.  The  power  of  a  thought 
was  illustrated  on  one  of  these  occasions.  I  had  descended 
with  extreme  slowness  and  caution  for  some  time,  when 
looking  over  the  edge  of  the  cornice  I  saw  a  row  of  point- 
ed rocks  at  some  distance  below  me.  These  I  felt  must 
receive  me  if  I  slipped  over,  and  I  thought  how  before 
reaching  them  I  might  so  break  my  fall  as  to  arrive  at 
them  unkilled.  This  thought  enabled  me  to  double  my 
speed,  and  as  long  as  the  spiky  barrier  ran  parallel  to  my 
track  I  held  my  staff  in  one  hand,  and  contented  myself 
with  a  slight  pressure  upon  it. 

I  came  at  length  to  a  place  where  the  edge  was  solid  ice, 
which  rose  to  the  level  of  the  cornice,  the  latter  appearing 
as  if  merely  stuck  against  it.  A  groove  ran  between  the 
ice  and  snow,  and  along  this  groove  I  marched  until  the 
cornice  became  unsafe,  and  I  had  to  betake  myself  to 
the  ice.  The  place  was  really  perilous,  but,  encouraging 
myself  by  the  reflection  that  it  would  not  last  long,  I  care- 
fully and  deliberately  hewed  steps,  causing  them  to  dip  a 
little  inward,  so  as  to  afford  a  purchase  for  the  heel  of  my 


1858.]  ACCIDENT   ON  THE   KAMM.  159 

boot,  never  forsaking  one  till  the  next  was  ready,  and  never 
wielding  my  hatchet  until  my  balance  was  secured.  I  was 
soon  at  the  bottom  of  the  Kamm,  fairly  out  of  danger,  and, 
full  of  glad  vigour,  I  bore  swiftly  down  upon  the  party  in 
advance  of  me.  It  was  an  easy  task  to  me  to  fuse  myself 
amongst  them  as  if  I  had  been  an  old  acquaintance,  and 
we  joyfully  slid,  galloped,  and  rolled  together  down  the 
residue  of  the  mountain. 

The  only  exception  was  the  young  gentleman  in 
Lauener' s  care.  A  day  or  two  previously  he  had,  I  believe, 
injured  himself  in  crossing  the  Gemmi,  and  long  before  he 
reached  the  summit  of  Monte  Rosa  his  knee  swelled,  and 
lie  walked  with  great  difficulty.  But  he  persisted  in 
ascending,  and  Lauener,  seeing  his  great  courage,  thought 
it  a  pity  to  leave  him  behind.  I  have  stated  that  a 
portion  of  the  Kamm  was  solid  ice.  On  descending  this, 
Mr.  F.'s  footing  gave  way,  and  he  slipped  forward. 
Lauener  was  forced  to  accompany  him,  for  the  place  was 
too  steep  and  slippery  to  permit  of  their  motion  being 
checked.  Both  were  on  the  point  of  going  over  the 
Lyskamm  side  of  the  mountain,  where  they  would  have 
indubitably  been  dashed  to  pieces.  "  There  was  no  escape 
there,"  said  Lauener,  in  describing  the  incident  to  me  sub- 
sequently, "  but  I  saw  a  possible  rescue  at  the  other  side, 
so  I  sprang  to  the  right,  forcibly  swinging  my  companion 
round ;  but  in  doing  so,  the  baton  tripped  me  up ;  we 
both  fell,  and  rolled  rapidly  over  each  other  down  the 
incline.  I  knew  that  some  precipices  were  in  advance  of 
us,  over  which  we  should  have  gone,  so,  releasing  myself 
from  my  companion,  I  threw  myself  in  front  of  him, 
stopped  myself  with  my  axe,  and  thus  placed  a  barrier  before 
him."  After  some  vain  efforts  at  sliding  down  the  slopes 
on  a  baton,  in  which  practice  I  was  fairly  beaten  by  some 
of  my  new  friends,  I  attached  myself  to  the  invalid,  and 
walked  with  him  and  Lauener  homewards.  Had  I  gone 


160  DANGER  OF   CLIMBING  ALONE.  [1858. 

forward  with  the  foremost  of  the  party,  I  should  have 
completed  the  expedition  to  the  summit  and  back  in  a 
little  better  than  nine  hours. 

I  think  it  right  to  say  one  earnest  word  in  con- 
nexion with  this  ascent :  and  the  more  so  as  I  believe  a 
notion  is  growing  prevalent  that  half  what  is  said  and 
written  about  the  dangers  of  the  Alps  is  mere  humbug. 
No  doubt  exaggeration  is  not  rare,  but  I  would  emphat- 
ically warn  my  readers  against  acting  upon  the  supposi- 
tion that  it  is  general.  The  dangers  of  Mont  Blanc,  Monte 
Rosa,  and  other  mountains,  are  real,  and,  if  not  properly 
provided  against,  may  be  terrible.  I  have  been  much 
accustomed  to  be  alone  upon  the  glaciers,  but  sometimes, 
even  when  a  guide  was  in  front  of  me,  I  have  felt  an  ex- 
treme longing  to  have  a  second  one  behind  me.  Less 
than  two  good  ones  I  think  an  arduous  climber  ought  not 
to  have ;  and  if  climbing  without  guides  were  to  become 
habitual,  deplorable  consequences  would  assuredly  sooner 
or  later  ensue. 


(23.) 

THE  18th  of  August  I  spent  upon  the  Furgge  glacier  at 
the  base  of  Mont  Cervin,  and  what  it  taught  me  shall  be 
stated  in  another  place.  The  evening  of  this  day  was 
signalized  by  the  pleasant  acquaintances  which  it  gave 
me.  It  was  my  intention  to  cross  the  Weissthor  on  the 
morning  of  the  19th,  but  thunder,  lightning,  and  heavy 
rain  opposed  the  project,  and  with  two  friends  I  descended, 
amid  pitiless  rain,  to  Zermatt.  Next  day  I  walked  by 
way  of  Stalden  to  Saas,  where  I  made  the  acquaintance  of 
Herr  Imseng,  the  Cure",  and  on  the  21st  ascended  to  the 
Distel  Alp.  Near  to  this  place  the  Allelein  glacier  pushes 
its  huge  terminus  right  across  the  valley  and  dams  up  the 


1858.]  ASCENT   OF  A  BOULDER.  161 

streams  descending  from  the  mountains  higher  up,  thus 
giving  birth  to  a  dismal  lake.  At  one  end  of  this  stands 
the  Mattmark  hotel,  which  was  to  be  my  head-quarters 
for  a  few  days. 

I  reached  the  place  in  good  company.  Near  to  the  hotel 
are  two  magnificent  boulders  of  green  serpentine,  which 
have  been  lodged  there  by  one  of  the  lateral  glaciers ;  and 
two  of  the  ladies  desiring  to  ascend  one  of  these  rocks,  a 
friend  and  myself  helped  them  to  the  top.  The  thing 
was  accomplished  in  a  very  spirited  way.  Indeed  the 
general  contrast,  in  regard  to  energy,  between  the  maidens 
of  the  British  Isles  and  those  of  the  Continent  and  of 
America  is  extraordinary.  Surely  those  who  talk  of  this 
country  being  in  its  old  age  overlook  the  physical  vigour 
of  its  sons  and  daughters.  They  are  strong,  but  from  a 
combination  of  the  greatest  forces  we  may  obtain  a  small 
resultant,  because  the  forces  may  act  in  opposite  direc- 
tions and  partly  neutralize  each  other.  Herein,  in  fact, 
lies  Britain's  weakness ;  it  is  strength  ill  directed  ;  and  is 
indicative  rather  of  the  perversity  of  young  blood  than  of 
the  precision  of  mature  years. 

Immediately  after  this  achievement  I  was  forsaken  by 
my  friends,  and  remained  the  only  occupant  of  the  hotel. 
A  dense  gray  cloud  gradually  filled  the  entire  atmosphere, 
from  which  the  rain  at  length  began  to  gush  in  torrents. 
The  scene  from  the  windows  of  the  hotel  was  of  the  most 
dismal  character;  the  rain  also  came  through  the  roof, 
and  dripped  from  the  ceiling  to  the  floor.  I  endeavoured 
to  make  a  fire,  but  the  air  would  not  let  the  smoke 
of  the  pine-logs  ascend,  and  the  biting  of  the  hydro- 
carbons was  excruciating  to  the  eyes.  On  the  whole, 
the  cold  was  preferable  to  the  smoke.  During  the 
night  the  rain  changed  to  snow,  and  on  the  morning  of 
the  22nd  all  the  mountains  were  thickly  covered.  The 
gray  delta,  through  which  a  river  of  many  arms  ran 
11 


162  DISMAL  QUABTEKS.  [1858. 

into  the  Mattmark  See,  was  hidden ;  against  some  of  the 
windows  of  the  salle  a  manger  the  snow  was  also  piled, 
obscuring  more  than  half  their  light.  I  had  sent  my  guide 
to  Yisp,  and  two  women  and  myself  were  the  only  occu- 
pants of  the  place.  It  was  extremely  desolate.  I  felt, 
moreover,  the  chill  of  Monte  Rosa  in  my  throat,  and  the 
conditions  were  not  favourable  to  the  cure  of  a  cold. 

On  the  23rd  the  Allelein  glacier  was  unfit  for  work ; 
I  therefore  ascended  to  the  summit  of  the  Monte  Moro, 
and  found  the  Valais  side  of  the  pass  in  clear  sunshine, 
while  impenetrable  fog  met  us  on  the  Italian  side.  I 
examined  the  colour  of  the  freshly  fallen  snow  ;  it  was 
not  an  ordinary  blue,  and  was  even  more  transparent 
than  the  blue  of  the  firmament.  When  the  snow  was 
broken  the  light  flashed  forth ;  when  the  staff  was  dug 
into  the  snow  and  withdrawn,  the  blue  gleam  appeared  ; 
when  the  staff  lay  in  a  hole,  although  there  might  be  a 
sufficient  space  all  round  it,  the  coloured  light  refused  to 
show  itself. 

My  cough  kept  me  awake  on  the  night  of  the  23rd,  and 
my  cold  was  worse  next  day.  I  went  upon  the  Allelein 
glacier,  but  found  myself  by  no  means  so  sure  a  climber 
as  usual.  The  best  guides  find  that  their  powers  vary  ; 
they  are  not  equally  competent  on  all  days.  I  have  heard 
a  celebrated  Chamouni  guide  assert  that  a  man's  morale 
is  different  on  different  days.  The  morale  in  my  case  had 
a  physical  basis,  and  it  probably  has  so  in  all.  The  Alle- 
lein glacier,  as  I  have  said,  crosses  the  valley  and  abuts 
against  the  opposite  mountain ;  here  it  is  forced  to  turn 
aside,  and  in  consequence  of  the  thrust  and  bending  it  is 
crumpled  and  crevassed.  The  wall  of  the  Mattmark  See  is 
a  fine  glacier  section  :  looked  at  from  a  distance,  the  ridges 
and  fissures  appear  arranged  like  a  fan.  The  structure 
of  the  crumpled  ice  varies  from  the  vertical  to  the  horizon- 
tal, and  the  ridges  are  sometimes  split  along  the  planes  of 


1858.]  THE   VAULT   OF  THE  ALLELEIN.  163 

structure.  The  aspect  of  this  portion  of  the  glacier  from 
some  of  the  adjacent  heights  is  exceedingly  interesting. 

On  the  morning  of  the  25th  I  had  two  hours'  clamber- 
ing over  the  mountains  before  breakfast,  and  traced  the 
action  of  ancient  glaciers  to  a  great  height.  The  valley 
of  Saas  in  this  respect  rivals  that  of  Hasli ;  the  flu  tings 
and  polishings  being  on  the  grandest  scale.  After  break- 
fast I  went  to  the  end  of  the  Allelein  glacier,  where  the 
Saas  Visp  river  rushes  from  it :  the  vault  was  exceedingly 
fine,  being  composed  of  concentric  arches  of  clear  blue  ice. 
I  spent  several  hours  here  examining  the  intimate  struc- 
ture of  the  ice,  and  found  the  vacuum  disks,  which  I  shall 
describe  at  another  place,  of  the  greatest  service  to  me. 
As  at  Rosenlaui  and  elsewhere,  they  here  taught  me  that 
the  glacier  was  composed  of  an  aggregate  of  small  frag- 
ments, each  of  which  had  a  definite  plane  of  crystalliza- 
tion. Where  the  ice  was  partially  weathered  the  surfaces 
of  division  between  the  fragments  could  be  traced  through 
the  coherent  mass,  but  on  crossing  these  surfaces  the  di- 
rection of  the  vacuum  disks  changed,  indicating  a  similar 
change  of  the  planes  of  crystallization.  The  blue  veins 
of  the  glacier  went  through  its  component  fragments  irre- 
spective of  these  planes.  Sometimes  the  vacuum  disks 
were  parallel  to  the  veins,  sometimes  across  them,  some- 
times oblique  to  them. 

Several  fine  masses  of  ice  had  fallen  from  the  arch  upon 
its  floor,  and  these  were  disintegrated  to  the  core.  A  kick, 
or  a  stroke  of  an  axe,  sufficed  to  shake  masses  almost  a 
cubic  yard  in  size  into  fragments  varying  not  much  on 
either  side  of  a  cubic  inch.  The  veining  was  finely  pre- 
served on  the  concentric  arches  of  the  vault,  and  some  of 
them  apparently  exhibited  its  abolition,  or  at  least  confu- 
sion, and  fresh  development  by  new  conditions  of  pressure. 
The  river  being  deep  and' turbulent  this  day,  to  reach  its 
opposite  side  I  had  to  climb  the  glacier  and  cross  over 


164  AVALANCHE  AT  SAAS.  [1858. 

the  crown  of  its  highest  arch  ;  this  enabled  me  to  get 
quite  in  front  of  the  vault,  to  enter  it,  and  closely  inspect 
those  portions  where  the  structure  appeared  to  change.  I 
afterwards  ascended  the  steep  moraine  which  lies  between 
the  Allelein  and  the  smaller  glacier  to  the  left  of  it, 
passing  to  the  latter  at  intervals  to  examine  its  struc- 
ture. I  was  at  length  stopped  by  the  dislocated  ice  ;  and 
from  the  heights  I  could  count  a  system  of  seven  dirt- 
bands,  formed  by  the  undulations  on  the  surface  of  the 
glacier.  On  my  return  to  the  hotel,  I  found  there  a  num- 
ber of  well-known  Alpine  men  who  intended  to  cross  the 
Adler  Pass  on  the  following  day.  Herr  Imseng  was  there : 
he  came  to  me  full  of  enthusiasm,  and  asked  me  whether 
I  would  join  him  in  an  ascent  of  the  Dom :  we  might  imme- 
diately attack  it,  and  he  felt  sure  that  we  should  succeed. 
The  Dom  is  the  highest  of  the  Mischabel  peaks,  and  is 
one  of  the  grandest  of  the  Alps.  I  agreed  to  join  the  Cure*, 
and  with  this  understanding  we  parted  for  the  night. 

Thursday,  26th  August.  —  A  wild  stormy  morning  after 
a  wild  and  rainy  night :  the  Adler  Pass  being  impassable, 
the  mountaineers  returned,  and  Imseng  informed  me  that 
the  Dom  must  be  abandoned.  He  gave  me  the  statistics 
of  an  avalanche  which  had  fallen  in  the  valley  some  years 
before.  Within  the  memory  of  man  Saas  had  never  been 
touched  by  an  avalanche,  but  a  tradition  existed  that  such 
a  catastrophe  had  once  occurred.  On  the  14th  of  March, 
1848,  at  eight  o'clock  in  the  morning,  the  Cure*  was  in  his 
room,  when  he  heard  the  cracking  of  pine-branches,  and 
inferred  from  the  sound  that  an  avalanche  was  descending 
upon  the  village.  It  dashed  in  the  windows  of  his  house 
and  filled  his  rooms  with  snow ;  the  sound  it  produced 
being  sufficient  to  mask  the  crashing  of  the  timbers  of  an 
adjacent  house.  Three  persons  were  killed.  On  the  3rd 
of  April,  1849,  heavy  snow  fell  at  Saas  ;  the  Cur6  waited 
until  it  had  attained  a  depth  of  four  feet,  and  then  re- 


1858.]  THE  FEE  GLACIER.  165 

treated  to  Fe*e.  That  night  an  avalanche  descended,  and 
in  the  line  of  its  rush  was  a  house  in  which  five  or  six  and 
twenty  people  had  collected  for  safety  :  nineteen  of  them 
were  killed.  The  Cur£  afterwards  showed  me  the  site  of 
the  house,  and  the  direction  of  the  avalanche.  It  passed 
through  a  pine  wood  ;  and  on  expressing  my  surprise  that 
the  trees  did  not  arrest  it,  he  replied  that  the  snow  was 
"  quite  like  dust,"  and  rushed  among  the  trees  like  so  much 
water.  To  return  from  F£e  to  Saas  on  the  day  following 
he  found  it  necessary  to  carry  two  planks.  Kneeling  upon 
one  of  them,  he  pushed  the  other  forward,  and  transferred 
his  weight  to  it,  drawing  the  other  after  him  and  repeating 
the  same  act.  The  snow  was  like  flour,  and  would  not 
otherwise  bear  his  weight.  Seeing  no  prospect  of  fine 
weather,  I  descended  to  Saas  on  the  afternoon  of  the  26th. 
I  was  the  only  guest  at  the  hotel ;  but  during  the  evening 
I  was  gratified  by  the  unexpected  arrival  of  my  friend 
Hirst,  who  was  on  his  way  over  the  Monte  Moro  to  Italy. 
For  the  last  five  days  it  had  been  a  struggle  between 
the  north  wind  and  the  south,  each  edging  the  other  by 
turns  out  of  its  atmospheric  bed,  and  producing  copious 
precipitation ;  but  now  the  conflict  was  decided,  —  the 
north  had  prevailed,  and  an  almost  unclouded  heaven 
overspread  the  Alps.  The  few  white  fleecy  masses  that 
remained  were  good  indications  of  the  swift  march  of  the 
wind  in  the  upper  air.  My  friend  and  I  resolved  to  have 
at  least  one  day's  excursion  together,  and  we  chose  for  it 
the  glacier  of  the  Fe*e.  Ascending  the  mountain  by  a 
well-beaten  path,  we  passed  a  number  of  "  Calvaries  " 
filled  with  tattered  saints  and  Virgins,  and  soon  came 
upon  the  rim  of  a  flattened  bowl  quite  clasped  by  the 
mountains.  In  its  centre  was  the  little  hamlet  of  Fe*e, 
round  which  were  fresh  green  pastures,  and  beyond  it  the 
perpetual  ice  and  snow.  It  was  exceedingly  picturesque, 
—  a  scene  of  human  beauty  and  industry  where  savagery 


166  SNOW,   VAPOUR,   AND    CLOUD.  [1858. 

alone  was  to  be  expected.  The  basin  had  been  scooped 
by  glaciers,  and  as  we  paused  at  its  entrance  the  rounded 
and  fluted  rocks  were  beneath  our  feet.  The  Alphubel 
and  the  Mischabel  raised  their  crowns  to  heaven  in  front 
of  us  ;  the  newly  fallen  snow  clung  where  it  could  to  the 
precipitous  crags  of  the  Mischabel,  but  on  the  summits  it 
was  the  sport  of  the  wind.  Sometimes  it  was  borne  straight 
upwards  in  long  vertical  striae  ;  sometimes  the  fibrous 
columns  swayed  to  the  right,  sometimes  to  the  left ; 
sometimes  the  motion  on  one  of  the  summits  would  quite 
subside  ;  anon  the  white  peak  would  appear  suddenly  to 
shake  itself  to  dust,  which  it  yielded  freely  to  the  wind. 
I  could  see  the  wafted  snow  gradually  melt  away,  and 
again  curdle  up  into  true  white  cloud  by  precipitation ; 
this  in  its  turn  would  be  pulled  asunder  like  carded  wool, 
and  reduced  a  second  time  to  transparent  vapour. 

In  the  middle  of  the  ice  of  the  Fe*e  stands  a  green  alp, 
not  unlike  the  Jardin  ;  up  this  we  climbed,  halting  at 
intervals  upon  its  grassy  knolls  to  inspect  the  glacier.  I 
aimed  at  those  places  where  on  a  priori  grounds  I  should 
have  thought  the  production  of  the  veined  structure  most 
likely,  and  reached  at  length  the  base  of  a  wall  of  rock 
from  the  edge  of  which  long  spears  of  ice  depended. 
Here  my  friend  halted,  while  Lauener  and  myself  climbed 
the  precipice,  and  ascended  to  the  summit  of  the  alp.  The 
snow  was  deep  at  many  places,  and  our  immersions  in 
oinseen  holes  very  frequent.  From  the  peak  of  the  Fde 
Alp  a  most  glorious  view  is  obtained  ;  in  point  of  gran- 
deur it  will  bear  comparison  with  any  in  the  Alps,  and 
its  seclusion  gives  it  an  inexpressible  charm.  We  re- 
mained for  half  an  hour  upon  the  warm  rock,  and  then 
descended.  It  was  our  habit  to  jump  from  the  higher 
ledges  into  the  deep  snow  below  them,  in  which  we  wal- 
lowed as  if  it  were  flour  ;  but  on  one  of  these  occasions  I 
lighted  on  a  stone,  and  the  shock  produced  a  curious  effect 


1858.]  "A  TERRIBLE   HOLE."  16T 

upon  my  hearing.  I  appeared  suddenly  to  lose  the  power 
of  appreciating  deep  sounds,  while  the  shriller  ones  were 
comparatively  unimpaired.  After  I  rejoined  my  friend  it 
required  attention  on  my  part  to  hear  him  when  he  spoke 
to  me.  This  continued  until  I  approached  the  end  of  the 
glacier,  when  suddenly  the  babblement  of  streams,  and  a 
world  of  sounds  to  which  I  had  been  before  quite  deaf 
burst  in  upon  me.  The  deafness  was  probably  due  to  a 
strain  of  the  tympanum,  such  as  we  can  produce  arti- 
ficially, and  thus  quench  low  sounds,  while  shrill  ones 
are  scarcely  affected. 

I  was  anxious  to  quit  Saas  early  next  morning,  but  the 
Cure  expressed  so  strong  a  wish  to  show  us  what  he  called 
a  Schauderhaftes  Loch  —  a  terrible  hole  —  which  he  had 
himself  discovered,  that -I  consented  to  accompany  him. 
We  were  joined  by  his  assistant  and  the  priest  of  Fe*e. 
The  stream  from  the  F£e  glacier  has  cut  a  deep  channel 
through  the  rocks,  and  along  the  right-hand  bank  of  the 
stream  we  ascended.  It  was  very  rough  with  fallen  crags 
and  fallen  pines,  amid  which  we  once  or  twice  lost  our 
way.  At  length  we  came  to  an  aperture  just  sufficient  to 
let  a  man's  body  through,  and  were  informed  by  our  con- 
ductor that  our  route  lay  along  the  little  tunnel :  he  lay 
down  upon  his  stomach  and  squeezed  himself  through  it 
like  a  marmot.  I  followed  him ;  a  second  tunnel,  in 
which,  however,  we  could  stand  upright,  led  into  a  spa- 
cious cavern,  formed  by  the  falling  together  of  immense 
slabs  of  rock  which  abutted  against  each  other  so  as  to 
form  a  roof.  It  was  the  very  type  of  a  robber  den  ;  and 
when  I  remarked  this,  it  was  at  once  proposed  to  sing  a 
verse  from  Schiller's  play.  The  young  clergyman  had  a 
powerful  voice,  —  he  led  and  we  all  chimed  in. 

"  Ein  frohes  Leben  fiihren  wir, 
Ein  Lcben  roller  Wonne. 
Der  Wald  1st  unser  Nachtquartier, 
Bei  Sturm  and  Wind  hanthieren  wir, 

^  T)p.r  TVTrmd  ist  nnsrfi  SnnnA ." 


168  SONG  OF   THE  ROBBERS.  [1858. 

Heir  Imseng  wore  his  black  coat ;  the  others  had  taken 
theirs  off,  but  they  wore  their  clerical  hats,  black  breeches 
and  stockings.  We  formed  a  singular  group  in  a  singu- 
lar place,  and  the  echoed  voices  mingled  strangely  with 
the  gusts  of  the  wind  and  the  rush  of  the  river. 

Soon  after  I  parted  from  my  friend,  and  descended  the 
valley  to  Yisp,  where  I  also  parted  with  my  guide.  He 
had  been  with  me  from  the  22nd  of  July  to  the  29th  of 
August,  and  did  his  duty  entirely  to  my  satisfaction. 
He  is  an  excellent  iceman,  and  is  well  acquainted  both 
with  the  glaciers  of  the  Oberland  and  of  the  Yalais.  He 
is  strong  and  good-humoured,  and  were  I  to  make  another 
expedition  of  the  kind  I  don't  think  that  I  should  take  any 
guide  in  the  Oberland  in  preference  to  Christian  Lauener. 


(24.) 

IT  is  a  singular  fact  that  as  yet  we  know  absolutely 
nothing  of  the  winter  temperature  of  any  one  of  the  high 
Alpine  summits.  No  doubt  it  is  a  sufficient  justification 
of  our  Alpine  men,  as  regards  their  climbing,  that  they 
like  it.  This  plain  reason  is  enough  ;  and  no  man  who 
ever  ascended  that  "  bad  eminence,"  Primrose  Hill,  or 
climbed  to  Hampstead  Heath  for  the  sake  of  a  freer  hori- 
zon, can  consistently  ask  a  better.  As  regards  physical 
science,  however,  the  contributions  of  our  mountaineers 
have  as  yet  been  nil,  and  hence,  when  we  hear  of  the  sci- 
entific value  of  their  doings,  it  is  simply  amusing  to  the 
climbers  themselves.  I  do  not  fear  that  I  shall  offend  them 
in  the  least  by  my  frankness  in  stating  this.  Their  plea- 
sure is  that  of  overcoming  acknowledged  difficulties,  and  of 
witnessing  natural  grandeur.  But  I  would  venture  to  urge 
that  our  Alpine  men  will  not  find  their  pleasure  lessened 
by  embracing  a  scientific  object  in  their  doings.  They 


1858.]  CLIMBERS  AND   SCIENCE.  169 

have  the  strength,  the  intelligence,  and  let  them  add  to 
these  the  accuracy  which  physical  science  now  demands, 
and  they  may  contribute  work  of  enduring  value.  Mr. 
Casella  will  gladly  teach  them  the  use  of  his  minimum- 
thermometers  ;  and  I  trust  that  the  next  seven  years 
will  not  pass  without  making  us  acquainted  with  the 
winter  temperature  of  every  mountain  of  note  in  Switzer- 
land.* 

I  had  thought  of  this  subject  since  I  first  read  the  con- 
jectures of  De  Saussure  on  the  temperature  of  Mont 
Blanc  ;  but  in  1857  I  met  Auguste  Balmat  at  the  Jardin, 
and  there  learned  from  him  that  he  entertained  the  idea 
of  placing  a  self-registering  thermometer  at  the  sum- 
mit of  the  mountain.  Balmat  was  personally  a  stranger 
to  me  at  the  time,  but  Professor  Forbes' s  writings  had 
inspired  me  with  a  respect  for  him,  which  this  un- 
prompted idea  of  his  augmented.  He  had  procured  a 
thermometer,  the  graduation  of  which,  however,  he  feared 
was  not  low  enough.  As  an  encouragement  to  Balmat, 
and  with  the  view  of  making  his  laudable  intentions 
known,  I  communicated  them  to  the  Royal  Society,  and 
obtained  from  the  Council  a  small  grant  of  money  to  pur- 
chase thermometers  and  to  assist  in  the  expenses  of  an  as- 
cent. I  had  now  the  thermometers  in  my  possession  ; 
and  having  completed  my  work  at  Zermatt  and  Saas,  my 
next  desire  was  to  reach  Chamouni  and  place  the  instru- 
ments on  the  top  of  Mont  Blanc.  I  accordingly  descend- 
ed the  valley  of  the  Rhone  to  Martigny,  crossed  the  Tete 
Noire,  and  arrived  at  Chamouni  on  the  29th  of  August, 
1858. 

Balmat  was  engaged  at  this  time  as  the  guide  of  Mr. 
Alfred  Wills,  who,  however,  kindly  offered  to  place  him 
at  my  disposal ;  and  also  expressed  a  desire  to  accom- 

*  I  find  with  pleasure  that  my  friend  Mr.  John  Ball  is  now  exerting  him- 
self in  this  direction. 


170  DIFFICULTIES   AT   CHAMOUNL  [1858. 

pany  me  himself  and  assist  me  in  my  observations.  I 
gladly  accepted  a  proposal  which  gave  me  for  com- 
panion so  determined  a  climber  and  so  estimable 
a  man.  But  Chamouiii  was  rife  with  difficulties.  In 
1857  the  Guide  Chef  had  the  good  sense  to  give  me 
considerable  liberty  of  action.  Now  his  mood  was  entirely 
changed  :  he  had  been  "  molested  "  for  giving  me  so  much 
freedom.  I  wished  to  have  a  boy  to  carry  a  small  instru- 
ment for  me  up  the  Mer  de  Glace,  —  he  would  not  allow 
it ;  I  must  take  a  guide.  If  I  ascended  Mont  Blanc  he  de- 
clared that  I  must  take  four  guides  ;  that,  in  short,  I  must 
in  all  respects  conform  to  the  rules  made  for  ordinary 
tourists.  I  endeavoured  to  explain  to  him  the  advantages 
which  Chamouni  had  derived  from  the  labours  of  men  of 
science  ;  it  was  such  men  who  had  discovered  it  when  it 
was  unknown,  and  it  was  by  their  writings  that  the  atten- 
tion of  the  general  public  had  been  called  towards  it.  It 
was  a  bad  recompense,  I  urged,  to  treat  a  man  of  science 
as  he  was  treating  me.  This  was  urged  in  vain  ;  he 
shrugged  his  shoulders,  was  very  sorry,  but  the  thing  could 
not  be  changed.  I  then  requested  to  know  his  superior, 
that  I  might  apply  to  him ;  he  informed  me  that  there 
were  a  President  and  Commission  of  guides  at  Chamouni, 
who  were  the  proper  persons  to  decide  the  question,  and 
he  proposed  to  call  them  together  on  the  31st  of  August, 
at  seven  P.M.,  on  condition  that  I  was  to  be  present  to 
state  my  own  case.  To  this  I  agreed. 

I  spent  that  day  quite  alone  upon  the  Mer  de  Glace, 
and  climbed  amid  a  heavy  snow-storm  to  the  Cleft  station 
over  Trelaporte.  When  I  reached  the  Montanvert  I  was 
wet  and  weary,  and  would  have  spent  the  night  there  were 
it  not  for  my  engagement  with  the  Guide  Chef.  I  de- 
scended amid  the  rain,  and  at  the  appointed  hour  went  to 
his  bureau.  He  met  me  with  a  polite  sympathetic  shrug ; 
explained  to  me  that  he  had  spoken  to  the  Commission, 


1858.]  THE  INTENDANT  MEMORIALISED.  171 

but  that  it  could  not  assemble  pour  une  chose  comme  $a ; 
that  the  rules  were  fixed,  and  I  must  abide  by  them. 
"  Well,"  I  responded,  "  you  think  you  have  done  your 
duty  ;  it  is  now  my  turn  to  perform  mine.  If  no  other 
means  are  available  I  will  have  this  transaction  commu- 
nicated to  the  Sardinian  Government,  and  I  don't  think 
that  it  will  ratify  what  you  have  done."  The  Guide  Chef 
evidently  did  not  believe  a  word  of  it. 

Previous  to  taking  any  further  step  I  thought  it  right 
so  see  the  President  of  the  Commission  of  Guides,  who  was 
also  Syndic  of  the  commune.  I  called  upon  him  on  the 
morning  of  the  1st  of  September,  and,  assuming  that  he 
knew  all  about  the  transaction,  spoke  to  him  accordingly. 
He  listened  to  me  for  a  time,  but  did  not  seem  to  under- 
stand me,  which  I  ascribed  partly  to  my  defective  French 
pronunciation.  I  expressed  a  hope  that  he  did  comprehend 
me ;  he  said  he  understood  my  words  very  well,  but  did 
not  know  their  purport.  In  fact  he  had  not  heard  a  sin- 
gle word  about  me  or  my  request.  He  stated  with  some 
indignation  that,  so  far  from  its  being  a  subject  on  which 
the  Commission  could  not  assemble,  it  was  one  which  it 
was  their  especial  duty  to  take  into  consideration.  Our 
conference  ended  with  the  arrangement  that  I  was  to 
write  him  an  official  letter  stating  the  case,  which  he  was 
to  forward  to  the  Intendant  of  the  province  of  Faucigny 
resident  at  Bonneville.  All  this  was  done. 

I  subsequently  memorialised  the  Intendant  himself ; 
and  Balmat  visited  him  to  secure  his  permission  to  ac- 
company me.  I  have  to  record,  that  from  first  to  last  the 
Intendant  gave  me  his  sympathy  and  support.  He  could 
not  alter  laws,  but  he  deprecated  a  "  judaical  "  inter- 
pretation of  them.  His  final  letter  to  myself  was  as 
follows :  — 


172  THE  INTENDANT'S  RESPONSE.  [1858. 

"  Intendance  Royale  de  la  Province  de  Faucigny, 
"Bonneville,  11  Septembre,  1858. 

"  Monsieur, — 

"  J'apprends  avec  une  veritable  peine  les  diffi- 
culte*s  que  vous  rencontrez  de  la  part  de  M.  le  Guide  Chef 
pour  1'effectuation  de  votre  pdrilleuse  entreprise  scienti- 
fique,  mais  je  dois  vous  dire  aussi  avec  regret  que  ces 
difficulty's  resident  dans  un  re*glement  fait  en  vue  de  la 
security  des  voyageurs,  quelque  puisse  etre  le  but  de  leurs 
excursions. 

"  Desireux  n^anmoins  de  vous  etre  utile  notamment  en 
la  circonstance,  j'invite  aujourd'hui  meme  M.  le  Guide 
Chef  a  avoir  £gard  a  votre  projet,  a  faire  en  sa  faveur  une 
exception  an  r^glement  ci  devant  eu,  tant  qu'il  n'y  aura 
aucun  danger  pour  votre  surete*  et  celles  des  personnes  qui 
vous  accompagneront,  et  enfin  de  se  preter  dans  les  limites 
de  ses  moyens  et  attributions  pour  1'heureux  success  de 
1'expedition,  dont  les  consequences  et  r^sultats  n'mte*res- 
sent  pas  seulement  la  science,  mais  encore  la  vallee  de 
Chamounix  en  particulier. 

"  Agre*ez,  Monsieur, 

"  Fassurance  de  ma  consideration  tres-distingu^e. 
"  Pour  1'Intendant  en  conge, 
"  Le  Secretaire, 

"  DELEGLISE." 

While  waiting  for  this  permission  I  employed  myself  ii 
various  ways.  On  the  2nd  of  September  I  ascended  the 
Brdvent,  from  which  Mont  Blanc  is  seen  to  great  advan 
tage.  From  Chamouni  its  vast  slopes  are  so  foreshortenec 
that  one  gets  a  very  imperfect  idea  of  the  extent  to  b< 
traversed  to  reach  the  summit.  What,  however,  struct 
me  most  on  the  Brevent  was  the  changed  relation  o 
the  Aiguille  du  Dm  and  the  Aiguille  Verte.  From  Mont 
anvert  the  former  appears  a  most  imposing  mass,  whil< 


1858.]  THE  "SERACS"  REVISITED.  173 

the  peak  of  the  latter  appears  rather  dwarfed  behind  it ; 
but  from  the  Ere* vent  the  Aiguille  du  Dru  is  a  mere 
pinnacle  stuck  in  the  breast  of  the  grander  pyramid  of 
the  Aiguille  Verte. 

On  the  4th  I  rose  early,  and,  strapping  on  my  telescope, 
ascended  to  the  Montanvert,  where  I  engaged  a  youth  to 
accompany  me  up  the  glacier.  The  heavens  were  clear 
and  beautiful :  —  blue  over  the  Aiguille  du  Dru,  blue  over 
the  Jorasse  and  Mont  Mallet,  deep  blue  over  the  pinnacles 
of  Charmoz,  and  the  same  splendid  tint  stretched  grandly 
over  the  Col  du  Ge*ant  and  its  Aiguille.  No  trace  of  con- 
densation appeared  till  towards  eleven  o'clock,  when  a 
ittle  black  balloon  of  cloud  swung  itself  over  the  Aiguilles 
Gouges.  At  one  o'clock  there  were  two  large  masses  and 
a  little  one  between  them ;  while  higher  up  a  white  veil, 
almost  too  thin  to  be  visible,  spread  over  a  part  of  the 
leavens.  At  the  zenith,  however,  and  south,  north,  and 
west,  the  blue  seemed  to  deepen  as  the  day  advanced.  I 
visited  the  ice-wall  at  the  Tacul,  which  seemed  lower 
:han  it  was  last  year ;  the  cascade  of  le  Ge*ant  appeared 
also  far  less  imposing.  Only  in  the  early  part  of  summer 
do  we  see  the  ice  in  its  true  grandeur :  its  edges  and  sur- 
?aces  are  then  sharp  and  clear,  but  afterwards  its  nobler 
masses  shrink  under  the  influence  of  sun  and  air.  The 
seracs  now  appeared  wasted  and  dirty,  and  not  the  sharp 
angular  ice-castles  which  rose  so  grandly  when  I  first  saw 
them.  Thirteen  men  had  crossed  the  Col  du  Ge*ant  on  the 
day  previous,  and  left  an  ample  trace  behind  them.  This 

followed  nearly  to  the  summit  of  the  fall.  The  con- 
dition of  the  glacier  was  totally  different  from  that  of 
the  opposite  side  on  the  previous  year.  The  ice  was 
riven,  burrowed,  and  honeycombed,  but  the  track  amid 
all  was  easy :  a  vigorous  English  maiden  might  have 
ascended  the  fall  without  much  difficulty.  My  object  now 
was  to  examine  the  structure  of  the  fall ;  but  the  ice  was 


174  THERMOMETER  AT   THE  JARDIN.  [1858. 

not  in  a  good  condition  for  such  an  examination  :  it  was 
too  much  broken.  Still  a  definite  structure  was  in  many 
places  to  be  traced,  and  some  of  them  apparently  showed 
structure  and  bedding  at  a  high  angle  to  each  other,  but 
I  could  not  be  certain  of  it.  I  paused  at  every  command- 
ing point  of  view  and  examined  the  ice  through  my  opera- 
glass  ;  but  the  result  was  inconclusive.  I  observed  that 
the  terraces  which  compose  the  fall  do  not  front  the  middle 
of  the  glacier,  but  turn  their  foreheads  rather  towards  its 
eastern  side,  and  the  consequence  is  that  the  protuberances 
lower  down,  which  are  the  remains  of  these  terraces,  are 
highest  at  the  same  side.  Standing  at  the  base  of  the 
Aiguille  Noire,  and  looking  downwards  where  the  Glacier 
des  Pe'riades  pushes  itself  against  the  Geant,  a  series  of  fine 
crumples  is  formed  on  the  former,  cut  across  by  crevasses, 
on  the  walls  of  which  a  forward  and  backward  dipping 
of  the  blue  veins  is  exhibited.  Huge  crumples  are  also 
formed  by  the  Glacier  du  Ge'ant,  which  are  well  seen  from 
a  point  nearly  opposite  the  lowest  lateral  moraine  of  the 
Glacier  des  Periades.  In  some  cases  the  upper  portions 
of  the  crumples  had  scaled  off  so  as  to  form  arches  of 
ice,  —  a  consequence  doubtless  of  the  pressure. 

The  beauty  of  some  Alpine  skies  is  treacherous  ;  in  fact, 
the  deepest  blue  often  indicates  an  atmosphere  charged 
almost  to  saturation  with  aqueous  vapour.  This  was  the 
case  on  the  present  occasion.  Soon  after  reaching  Chamouni 
in  the  evening,  rain  commenced  and  continued  with  scarcely 
any  intermission  until  the  afternoon  of  the  8th.  I  had 
given  up  all  hopes  of  being  able  to  ascend  Mont  Blanc ; 
and  hence  resolved  to  place  the  thermometers  in  some 
more  accessible  position.  On  the  9th  accordingly,  accom- 
panied by  Mr.  Wills,  Balmat,  and  some  other  friends,  I 
ascended  to  the  summit  of  the  Jardin,  where  we  placed 
two  thermometers :  one  in  the  ice,  at  a  depth  of  three  feet 
below  the  surface ;  another  on  a  ledge  of  the  highest 


1858.];  EVENING  BED.  175 

rock.*  The  boiling-point  of  water  at  this  place  was  194.6° 
Fahr. 

Deep  snow  was  upon  the  Talefre,  and  the  surrounding 
precipices  were  also  heavily  laden.  Avalanches  thundered 
incessantly  from  the  Aiguille  Yerte  and  the  other  moun- 
tains. Scarcely  five  minutes  on  an  average  intervened 
between  every  two  successive  peals ;  and  after  the  direct 
shock  of  each  avalanche  had  died  away,  the  air  of  the 
)asin  continued  to  be  shaken  by  the  echos  reflected  from 
.ts  bounding  walls. 

The  day  was  far  spent  before  we  had  completed  our 

work.   All  through  the  weather  had  been  fine,  and  towards 

ivening  augmented  to  magnificence.     As  we  descended 

the  glacier  from  the  Couvercle  the  sun  was  just  disappear- 

ng,  and  the  western  heaven  glowed  with  crimson,  which 

crept  gradually  up  the  sky  until  finally  it  reached  the 

zenith  itself.     Such  intensity  of  colouring  is  exceedingly 

rare  in  the  Alps ;    and  this  fact,  together  with  the  known 

ariations  in  the  intensity  of  the  firmamental  blue,  justify 

the  conclusion  that  the  colouring  must,  in  a  great  measure, 

)e  due  to  some  variable  constituent  of  the  atmosphere.   If 

'he  air  were  competent  to  produce  these  magnificent  effects 

they  would  be  the  rule  instead  of  the  exception. 

No  sooner  had  the  thermometers  been  thus  disposed  of 
;han  the  weather  appeared  to  undergo  a  permanent  change. 
On  the  10th  it  was  perfectly  fine,  —  not  the  slightest  mist 
upon  Mont  Blanc;  on  the  llth  this  was  also  the  case. 
Balmat  still  had  the  old  thermometer  to  which  I  have 
already  referred ;  it  might  not  do  to  show  the  minimum 
;emperature  of  the  air,  but  it  might  show  the  temperature 
at  a  certain  depth  below  the  surface.  I  find  in  my  own 
3ase  that  the  finishing  of  work  has  a  great  moral  value : 

*  The  minimum  temperature  of  the  subsequent  winter,  as  shown  by  this 
hermometer,  was  — 6°  Fahr.,  or  38°  below  the  freezing  point.  The  instru- 
nent  placed  in  the  ice  was  broken. 


176  FINISHED   WORK.  [1858. 

work  completed  is  a  safe  fulcrum  for  the  performance  of 
other  work  ;  and  even  though  in  the  course  of  our  labours 
experience  should  show  us  a  better  means  of  accomplish- 
ing a  given  end,  it  is  often  far  preferable  to  reach  the  end, 
even  by  defective  means,  than  to  swerve  from  our  course. 
The  habits  which  this  conviction  had  superinduced  no 
doubt  influenced  me  when  I  decided  on  placing  Balmat's 
thermometer  on  the  summit  of  Mont  Blanc. 


1858]  SHADOWS   OF   THE  AIGUILLES.  177 


SECOND  ASCENT  OF  MONT  BLANC,  1858. 

(25.) 

ON  the  12th  of  September,  at  5J  A.  M.  the  sunbeams 
had  already  fallen  upon  the  mountain ;  but  though  the 
sky  above  him,  and  over  the  entire  range  of  the  Aiguilles, 
was  without  a  cloud,  the  atmosphere  presented  an  appear- 
ance of  turbidity  resembling  that  produced  by  the  dust 
and  thin  smoke  mechanically  suspended  in  a  London  at- 
mosphere on  a  dry  summer's  day.  At  20  minutes  past  7 
we  quitted  Chamouni,  bearing  with  us  the  good  wishes  of 
a  portion  of  its  inhabitants. 

A  lady  accompanied  us  on  horseback  to  the  point  where 
the  path  to  the  Grands  Mulcts  deviates  from  that  to  the 
Plan  des  Aiguilles  ;  here  she  turned  to  the  left,  and  we 
proceeded  slowly  upwards,  through  woods  of  pine,  hung 
with  fantastic  lichens :  escaping  from  the  gloom  of  these, 
we  emerged  upon  slopes  of  bosky  underwood,  green  hazel, 
and  green  larch,  with  the  red  berries  of  the  mountain- 
ash  shining  brightly  between  them.  Through  the  air 
above  us,  like  gnomons  of  a  vast  sun-dial,  the  Aiguilles 
cast  their  fanlike  shadows,  which  moved  round  as  the  day 
advanced.  Slopes  of  rhododendrons  with  withered  flow- 
ers next  succeeded,  but  the  colouring  of  the  bilberry-leaves 
was  scarcely  less  exquisite  than  the  freshest  bloom  of  the 
Alpine  rose.  For  a  long  time  we  were  in  the  cool  shadow 
of  the  mountain,  catching,  at  intervals,  through  the  twigs 
in  front  of  us,  glimpses  of  the  sun  surrounded  by  coloured 
spectra.  On  one  occasion  a  brow  rose  in  front  of  me  ;  be- 
hind it  was  a  lustrous  space  of  heaven,  adjacent  to  the 
sun,  which,  however,  was  hidden  behind  the  brow;  against 
this  space  the  twigs  and  weeds  upon  the  summit  of  the 
12 


178  INTERFERENCE   SPECTRA.  [1858. 

brow  shone  as  if  they  were  self-luminous,  while  some  bits 
of  thistle-down  floating  in  the  air  appeared,  where  they 
crossed  this  portion  of  the  heavens,  like  fragments  of  the 
sun  himself.  Once  the  orb  appeared  behind  a  rounded 
mass  of  snow  which  lay  near  the  summit  of  the  Aiguille 
du  Midi.  Looked  at  with  the  naked  eyes,  it  seemed  to  pos- 
sess a  billowy  motion,  the  light  darting  from  it  in  dazzling 
curves,  —  a  subjective  effect  produced  by  the  abnormal 
action  of  the  intense  light  upon  the  eye.  As  the  sun's  disk 
came  more  into  view,  its  rays  however  still  grazing  the 
summit  of  the  mountain,  interference-spectra  darted  from 
it  on  all  sides,  and  surrounded  it  with  a  glory  of  richly- 
coloured  bars.  Mingling  however  with  the  grandeur  of 
nature,  we  had  the  anger  and  obstinacy  of  man.  With  a 
view  to  subsequent  legal  proceedings,  the  Guide  Chef  sent  a 
spy  after  us,  who,  having  satisfied  himself  of  our  delinquen- 
cy, took  his  unpleasant  presence  from  the  splendid  scene. 

Strange  to  say,  though  the  luminous  appearance  of 
bodies  projected  against  the  sky  adjacent  to  the  rising  sun 
is  a  most  striking  and  beautiful  phenomenon,  it  is  hardly 
ever  seen  by  either  guides  or  travellers  ;  probably  because 
they  avoid  looking  towards  a  sky  the  brightness  of  which 
is  painful  to  the  eyes.  In  1859  Auguste  Balmat  had 
never  seen  the  effect ;  and  the  only  written  description  of 
it  which  we  possess  is  one  furnished  by  Professor  Necker, 
in  a  letter  to  Sir  David  Brewster,  which  is  so  interesting 
that  I  do  not  hesitate  to  reproduce  it  here. 

"  I  now  come  to  the  point,"  writes  M.  Necker, "  which 
you  particularly  wished  me  to  describe  to  you ;  I  mean 
the  luminous  appearance  of  trees,  shrubs,  and  birds,  when 
seen  from  the  foot  of  a  mountain  a  little  before  sunrise. 
The  wish  I  had  to  see  again  the  phenomenon  before  at- 
tempting to  describe  it  made  me  detain  this  letter  a  few 
days,  till  I  had  a  fine  day  to  go  to  see  it  at  the  Mont  Sa- 
leve  ;  so  yesterday  I  went  there,  and  studied  the  fact,  and 


1358.]  PROFESSOR  NECKER'S  LETTER.  179 

iii  elucidation  of  it  I  made  a  little  drawing,  of  which  I 
give  you  here  a  copy  :  it  will,  with  the  explanation  and  the 
annexed  diagram  (Fig.  9),  impart  to  you,  I  hope,  a  correct 
idea  of  the  phenomenon.  You  must  conceive  the  observer 
placed  at  the  foot  of  a  hill  interposed  between  him  and 
the  place  where  the  sun  is  rising,  and  thus  entirely  in  the 
shade  ;  the  upper  margin  of  the  mountain  is  covered  with 
woods  or  detached  trees  and  shrubs,  which  are  projected 
as  dark  objects  on  a  very  bright  and  clear  sky,  except  at 
the  very  place  where  the  sun  is  just 'going  to  rise;  for 
there  all  the  trees  and  shrubs  bordering  the  margin  are 
entirely  —  branches,  leaves,  stem  and  all  —  of  a  pure  and 
brilliant  white,  appearing  extremely  bright  and  luminous, 
as  that  part  of  it  which  surrounds  the  sun  always  is.  All 
the  minutest  details,  leaves,  twigs,  <fcc.,  are  most  delicately 
preserved,  and  you  would  fancy  you  saw  these  trees  and 
forests  made  of  the  purest  silver,  with  all  the  skill  of  the 
most  expert  workman.  The  swallows  and  other  birds 
flying  in  those  particular  spots  appear  like  sparks  of  the 
most  brilliant  white.  Unfortunately,  all  these  details, 
which  add  so  much  to  the  beauty  of  this  splendid  pheno- 
menon, cannot  be  represented  in  such  small  sketches. 

"  Neither  the  hour  of  the  day  nor  the  angle  which  the 
object  makes  with  the  observer  appears  to  have  any  effect  : 
for  on  some  occasions  I  have  seen  the  phenomenon  take 
place  at  a  very  early  hour  in  the  morning.  Yesterday 
it  was  10  A.  M.,  when  I  saw  it  as  represented  in  Fig.  10. 
I  saw  it  again  on  the  same  day  at  5  P.  M.,  at  a  different 
place  of  the  same  mountain,  for  which  the  sun  was  just 
setting.  At  one  time  the  angle  of  elevation  of  the  lighted 
white  shrubs  above  the  horizon  of  the  spectator  was  about 
20°,  while  at  another  place  it  was  only  15°.  But  the  ex- 
tent of  the  field  of  illumination  is  variable,  according  to 
the  distance  at  which  the  spectator  is  placed  from  it. 


180 


SILVER  TREES  AT   SUNRISE. 


[1858. 


When  the  object  behind  which  the  sun  is  just  going  to 
rise,  or  has  just  been  setting,  is  very  near,-  no  such  effect 

takes  place.  In  the  case 
represented  in  Fig.  9  the 
distance  was  about  194 
metres,  or  636  English 
feet,  from  the  spectator  in 
a  direct  line,  the  height 
above  his  level  being  60 
metres,  or  19T  English 
feet,  and  the  horizontal 
line  drawn  from  him  to 
the  horizontal  projection 
of  these  points  on  the 
plane  of  his  horizon  being 
160  metres,  or  525  Eng- 
lish feet,  as  will  be  seen 
in  the  following  diagram, 
Fig.  10. 

"  In  this  case  only  small  shrubs  and  the  lower  half  of  the 
stem  of  a  tree  are  illuminated  white,  and  the  horizontal 

extent  of  this  effect 
is  also  comparative- 
ly small ;  while  at 
other  places,  when  I 

near  the  edg° 
Fig.  IB.  behind   which   the 

sun  was  going  to  rise,  no  such  effect  took  place.  But  on 
the  contrary,  when  I  have  witnessed  the  phenomenon  at  a 
greater  distance  and  at  a  greater  height,  as  I  have  seen  it 
other  times  on  the  same  and  on  other  mountains  of  the 
Alps,  large  tracts  of  forests  and  immense  spruce-firs  were 
illuminated  white  throughout  their  whole  length,  as  I  have 
attempted  to  represent  in  Fig.  11,  and  the  corresponding 
diagram,  Fig.  12.  Nothing  can  be  finer  than  these  silver- 


1858.] 


BIRDS  AS  SPARKS  OR  STARS. 


181 


looking  spruce-forests.  At  the  same  time,  though  at  a 
distance  of  more  than  a  thousand  metres,  a  vast  number  of 
large  swallows  or  swifts 
(  Cypselus  alpinus),  which 
inhabit  these  high  rocks, 
were  seen  as  small  bril- 
liant stars  or  sparks  mov- 
ing rapidly  in  the  air. 
From  these  facts  it  ap- 
pears to  me  obvious  that 
the  extent  of  the  illumi- 
nated spots  varies  in  a  di- 
rect ratio  of  their  distance ; 
but  at  the  same  time  that 
there  must  be  a  constant 
angular  space,  correspond- 
ing probably  to  the  zone, 
a  few  minutes  of  a  de- 
gree wide,  around  the 
sun's  disk,  which  is  a  limit 
to  the  occurrence  of  the  appearance.  This  would  explain 
how  the  real  extent  which  it  occupies  on  the  earth's  surface 
varies  with  the  relative  distance  of  the  spot  from  the  eye  of 
the  observer,  and  accounts  also  for  the  phenomenon  being 


C 


Fig.  11. 


Fig.  12. 


never  seen  in  the  low  country,  where  I  have  often  looked  for 
it  in  vain.  Now  that  you  are  acquainted  with  the  circum- 
stances of  the  fact,  I  have  no  doubt  you  will  easily  observe 
it  in  some  part  or  other  of  your  Scotch  hills  ;  it  may  be 


182  THE  LADDER   CONDEMNED.  [1858. 

some  long  heather  or  furze  will  play  the  part  of  our 
Alpine  forests,  and  I  would  advise  you  to  try  and  place  a 
bee-hive  in  the  required  position,  and  it  would  perfectly 
represent  our  swallows,  sparks,  and  stars." 

Our  porters,  with  one  exception,  reached  the  Pierre 
PEchelle  as  soon  as  ourselves ;  and  here  having  refreshed 
themselves,  and  the  due  exchange  of  loads  having  been 
made,  we  advanced  upon  the  glacier,  which  we  crossed, 
until  we  came  nearly  opposite  to  the  base  of  the  Grands 
Mulets.  The  existence  of  one  wide  crevasse,  which  was 
deemed  impassable,  had  this  year  introduced  the  practice 
of  assailing  the  rocks  at  their  base,  and  climbing  them  to 
the  cabin,  an  operation  which  Balmat  wished  to  avoid. 
At  Chamouni,  therefore,  he  had  made  inquiries  regarding 
the  width  of  the  chasm,  and,  acting  on  his  advice,  I  had 
had  a  ladder  constructed  in  two  pieces,  which,  united  to- 
gether by  iron  attachments,  was  supposed  to  be  of  suffi- 
cient length  to  span  the  fissure.  On  reaching  the  latter, 
the  pieces  were  united,  and  the  ladder  thrown  across,  but 
the  bridge  was  so  frail  and  shaky  at  the  place  of  junction, 
and  the  chasm  so  deep,  that  Balmat  pronounced  the  pas- 
sage impracticable. 

The  porters  were  all  grouped  beside  the  crevasse  when 
this  announcement  was  made,  and,  like  hounds  in  search 
of  the  scent,  the  group  instantly  broke  up,  seeking  in  all 
directions  for  a  means  of  passage.  The  talk  was  incessant 
and  animating :  attention  was  now  called  in  one  direction, 
anon  in  another,  the  men  meanwhile  throwing  themselves 
into  the  most  picturesque  groups  and  attitudes.  All  eyes 
at  length  were  directed  upon  a  fissure  which  was  spanned 
at  one  point  by  an  arch  of  snow,  certainly  under  two  feet 
deep  at  the  crown.  A  stout  rope  was  tied  round  the  waist 
of  one  of  our  porters,  and  he  was  sent  forward  to  test  the 
bridge.  He  approached  it  cautiously,  treading  down  the 
snow  to  give  it  compactness,  and  thus  make  his  footing 


1858.]  CROSSING  CREVASSES.  183 

sure  as  he  advanced  ;  bringing  regelation  into  play,  he 
gave  the  mass  the  necessary  continuity,  and  crossed  in 
safety.  The  rope  was  subsequently  stretched  over  the 
pont,  and  each  of  us  causing  his  right  hand  to  slide  along 
it,  followed  without  accident.  Soon  afterwards,  however, 
we  met  with  a  second  and  very  formidable  crevasse,  to 
cross  which  we  had  but  half  of  our  ladder,  which  was  ap- 
plied as  follows:  —  The  side  of  the  fissure  on  which  we 
stood  was  lower  than  the  opposite  one  ;  over  the  edge  of 
the  latter  projected  a  cornice  of  snow,  and  a  ledge  of  the 
same  material  jutted  from  the  wall  of  the  crevasse  a  little 
below  us.  The  ladder  was  placed  from  ledge  to  cornice, 
both  of  its  ends  being  supported  by  snow.  I  could  hardly 
believe  that  so  frail  a  bearing  could  possibly  support  a 
man's  weight ;  but  a  porter  was  tied  as  before,  and  sent 
up  the  ladder,  while  we  followed  protected  by  the  rope. 
We  were  afterwards  tied  together,  and  thus  advanced  in 
an  orderly  line  to  the  Grands  Mulets. 

The  cabin  was  wet  and  disagreeable,  but  the  sunbeams 
fell  upon  the  brown  rocks  outside,  and  thither  Mr.  Wills 
and  myself  repaired  to  watch  the  changes  of  the  atmo- 
sphere. I  took  possession  of  the  flat  summit  of  a  prism 
of  rock,  where,  lying  upon  my  back,  I  watched  the  clouds 
forming,  and  melting,  and  massing  themselves  together, 
and  tearing  themselves  like  wool  asunder  in  the  air  above. 
It  was  nature's  language  addressed  to  the  intellect  ; 
these  clouds  were  visible  symbols  which  enabled  us  to 
understand  what  was  going  on  in  the  invisible  air.  Here 
unseen  currents  met,  possessing  different  temperatures, 
mixing  their  contents  both  of  humidity  and  motion,  pro- 
ducing a  mean  temperature  unable  to  hold  their  moisture 
in  a  state  of  vapour.  The  water-particles,  obeying  their 
mutual  attractions,  closed  up,  and  a  visible  cloud  suddenly 
shook  itself  out,  where  a  moment  before  we  had  the  pure 
blue  of  heaven.  Some  of  the  clouds  were  wafted  by  the 


184  GORGEOUS  SUNSET.  [1858. 

air  towards  atmospheric  regions  already  saturated  with 
moisture,  and  along  their  frontal  borders  new  cloudlets 
ever  piled  themselves,  while  the  hinder  portions,  invaded 
by  a  drier  or  a  warmer  air,  were  dissipated  ;  thus  the 
cloud  advanced,  with  gain  in  front  and  loss  behind,  its  per- 
manence depending  on  the  balance  between  them.  The 
day  waned,  and  the  sunbeams  began  to  assume  the  colour- 
ing due  to  their  passage  through  the  horizontal  air.  The 
glorious  light,  ever  deepening  in  colour,  was  poured  boun- 
teously over  crags,  and  snows,  and  clouds,  and  suffused 
with  gold  and  crimson  the  atmosphere  itself.  I  had  never 
seen  anything  grander  than  the  sunset  on  that  day. 
Clouds  with  their  central  portions  densely  black,  denying 
all  passage  to  the  beams  which  smote  them,  floated 
westward,  while  the  fiery  fringes  which  bordered  them 
were  rendered  doubly  vivid  by  contrast  with  the  adjacent 
gloom.  The  smaller  and  more  attenuated  clouds  were 
intensely  illuminated  throughout.  Across  other  inky 
masses  were  drawn  zigzag  bars  of  radiance  which  re- 
sembled streaks  of  lightning.  The  firmament  between 
the  clouds  faded  from  a  blood-red  through  orange  and 
daffodil  into  an  exquisite  green,  which  spread  like  a 
sea  of  glory  through  which  those  magnificent  argosies 
slowly  sailed.  Some  of  the  clouds  were  drawn  in  straight 
chords  across  the  arch  of  heaven,  these  being  doubtless 
the  sections  of  layers  of  cloud  whose  horizontal  dimen- 
sions were  hidden  from  us.  The  cumuli  around  and  near 
the  sun  himself  could  not  be  gazed  upon,  until,  as  the 
day  declined,  they  gradually  lost  their  effulgence  and 
became  tolerable  to  the  eyes.  All  was  calm  —  but  there 
was  a  wildness  in  the  sky  like  that  of  anger,  which  boded 
evil  passions  on  the  part  of  the  atmosphere.  The  sun 
at  length  sank  behind  the  hills,  but  for  some  time  after- 
wards carmine  clouds  swung  themselves  on  high,  and  cast 
their  ruddy  hues  upon  the  mountain  snows.  Duskier  and 


1853.]  STORM  ON  THE  GRANDS  MULETS.  185 

colder  waxed  the  west,  colder  and  sharper  the  breeze 
of  evening  upon  the  Grands  Mulets,  and  as  twilight 
deepened  towards  night,  and  the  stars  commenced  to 
twinkle  through  the  chilled  air,  we  retired  from  the 
scene. 

The  anticipated  storm  at  length  gave  notice  of  its 
coming.  The  sea- waves,  as  observed  by  Aristotle,  some- 
times reach  the  shore  before  the  wind  which  produces 
them  is  felt ;  and  here  the  tempest  sent  out  its  precursors, 
which  broke  in  detached  shocks  upon  the  cabin  before  the 
real  storm  arrived.  Billows  of  air,  in  ever  quicker  suc- 
cession, rolled  over  us  with  a  long  surging  sound,  rising 
and  falling  as  crest  succeeded  trough  and  trough  succeed- 
ed crest.  And  as  the  pulses  of  a  vibrating  body,  when 
their  succession  is  quick  enough,  blend  to  a  continuous 
note,  so  these  fitful  gusts  linked  themselves  finally  to  a 
storm  which  made  its  own  wild  music  among  the  crags. 
Grandly  it  swelled,  carrying  the  imagination  out  of  doors, 
to  the  clouds  and  darkness,  to  the  loosened  avalanches 
and  whirling  snow  upon  the  mountain  heads.  Moored  to 
the  rock  on  two  sides,  the  cabin  stood  firm,  and  its  mani- 
fest security  allowed  the  mind  the  undisturbed  enjoyment 
of  the  atmospheric  war.  We  were  powerfully  shaken,  but 
had  no  fear  of  being  uprooted ;  and  a  certain  grandeur  of 
the  heart  rose  responsive  to  the  grandeur  of  the  storm. 
Mounting  higher  and  higher,  it  at  length  reached  its 
maximum  strength,  from  which  it  lowered  fitfully,  until 
at  length,  with  a  melancholy  wail,  it  bade  our  rock  fare- 
well. 

A  little  before  half-past  one  we  issued  from  the  cabin. 
The  night  being  without  a  moon,  we  carried*  three  lan- 
terns. The  heavens  were  crowded  with  stars,  among 
which,  however,  angry  masses  of  cloud  here  and  there 
still  wandered.  The  storm,  too,  had  left  a  rear-guard 
behind  it ;  and  strong  gusts  rolled  down  upon  us  at  inter- 


186  A   COMET  DISCOVERED.  [1858. 

vals,  at  one  time,  indeed,  so  violent  as  to  cause  Balmat  to 
express  doubts  of  our  being  able  to  reach  the  summit. 
With  a  thick  handkerchief  bound  around  my  hat  and  ears 
I  enjoyed  the  onset  of  the  wind.  Once,  turning  my  head 
to  the  left,  I  saw  what  appeared  to  me  to  be  a  huge  mass 
of  stratus  cloud,  at  a  great  distance,  with  the  stars  shining 
over  it.  In  another  instance  a  precipice  of  neve  loomed 
upon  us  ;  we  were  close  to  its  base,  and  along  its  front  the 
annual  layers  were  separated  from  each  other  by  broad 
dark  bands.  Through  the  gloom  it  appeared  like  a  cloud, 
the  lines  of  bedding  giving  to  it  the  stratus  character. 

Immediately  before  lying  down  on  the  previous  evening 
I  had  opened  the  little  window  of  the  cabin  to  admit  some 
air.  In  the  sky  in  front  of  me  shone  a  curious  nodule  of 
misty  light  with  a  pale  train  attached  to  it.  In  1853,  on 
the  side  of  the  Brocken,  I  had  observed,  without  previous 
notice,  a  comet  discovered  a  few  days  previously  by  a 
former  fellow-student,  and  here  was  another  "  discovery  " 
of  the  same  kind.  I  inspected  the  stranger  with  my  tele- 
scope, and  assured  myself  that  it  was  a  comet.  Mr.  Wills 
chanced  to  be  outside  at  the  time,  and  made  the  same 
observation  independently.  As  we  now, advanced  up  the 
mountain  its  ominous  light  gleamed  behind  us,  while 
high  up  in  heaven  to  our  left  the  planet  Jupiter  burned 
like  a  lamp  of  intense  brightness.  The  Petit  Plateau 
forms  a  kind  of  reservoir  for  the  avalanches  of  the  D6me 
du  Goute,  and  this  year  the  accumulation  of  frozen  debris 
upon  it  was  enormous.  We  could  see  nothing  but  the 
ice-blocks  on  which  the  light  of  the  lanterns  immediately 
fell ;  we  only  knew  that  they  had  been  discharged  from  the 
seracs,  and  that  similar  masses  now  rose  threatening  to  our 
right,  and  might  at  any  moment  leap  down  upon  us.  Bal- 
mat commanded  silence,  and  urged  us  to  move  across  the 
plateau  with  all  possible  celerity.  The  warning  of  our 
guide,  the  wild  and  rakish  appearance  of  the  sky,  the  spent 


1858.]  DAWN  ON  THE   GRAND  PLATEAU.  187 

projectiles  at  our  feet,  and  the  comet  with  its  "  horrid 
hair"  behind,  formed  a  combination  eminently  calculated 
to  excite  the  imagination. 

And  now  the  sky  began  to  brighten  towards  dawn,  with 
that  deep  and  calm  beauty  which  suggests  the  thought  of 
adoration  to  the  human  mind.  Helped  by  the  contem- 
plation of  the  brightening  east,  which  seemed  to  lend 
lightness  to  our  muscles,  we  cheerily  breasted  the  steep 
slope  up  to  the  Grand  Plateau.  The  snow  here  was  deep, 
and  each  of  our  porters  took  the  lead  in  turn.  We 
paused  upon  the  Grand  Plateau  and  had  breakfast ;  dig- 
ging, while  we  halted,  our  feet  deeply  into  the  snow. 
Thence  up  to  the  corridor,  by  a  totally  different  route 
from  that  pursued  by  Mr.  Hirst  and  myself  the  year  pre- 
viously ;  the  slope  was  steep,  but  it  had  not  a  precipice  for 
its  boundary.  Deep  steps  were  necessary  for  a  time,  but 
when  we  reached  the  summit  our  ascent  became  more  gen- 
tle. The  eastern  sky  continued  to  brighten,  and  by  its  illu- 
mination the  Grand  Plateau  and  its  bounding  heights  were 
lovely  beyond  conception.  The  snow  was  of  the  purest 
white,  and  the  glacier,  as  it  pushed  itself  on  all  sides  into 
the  basin,  was  riven  by  fissures  filled  with  a  cerulean  light, 
which  deepened  into  inky  gloom  as  the  vision  descended 
into  them.  The  edges  were  overhung  with  fretted  cornices, 
from  which  depended  long  clear  icicles,  tapering  from  their 
abutments  like  spears  of  crystal.  The  distant  fissures,  across 
which  the  vision  ranged  obliquely  without  descending  into 
them,  emitted  that  magical  firmamental  shimmer  which, 
contrasted  with  the  pure  white  of  the  snow,  was  inexpressi- 
bly lovely.  Near  to  us  also  grand  castles  of  ice  reared  them- 
selves, some  erect,  some  overturned,  with  clear  cut  sides, 
striped  by  the  courses  of  the  annual  snows,while  high  above 
the  seracs  of  the  plateau  rose  their  still  grander  brothers 
of  the  Dome  du  Goute.  There  was  a  nobility  in  this  gla- 
cier scene  which  I  think  I  have  never  seen  surpassed  ;  — 


188  BALMAT   IN  DANGER.  [1858. 

a  strength  of  nature,  and  yet  a  tenderness,  which  at  once 
raised  and  purified  the  soul.  The  gush  of  the  direct  sun- 
light could  add  nothing  to  this  heavenly  beauty  ;  indeed, 
I  thought  its  yellow  beams  a  profanation,  as  they  crept 
down  from  the  humps  of  the  Dromedary,  and  invaded 
more  and  more  the  solemn  purity  of  the  realm  below. 

Our  way  lay  for  a  time  amid  fine  fissures  with  blue 
walls,  until  at  length  we  reached  the  edge  of  one  which 
elicited  other  sentiments  than  those  of  admiration.  It 
must  be  crossed.  At  the  opposite  side  was  a  high  and 
steep  bank  of  ice  which  prolonged  itself  downwards,  and 
ended  in  a  dependent  eave  of  snow  which  quite  overhung 
the  chasm,  and  reached  to  within  about  a  yard  of  our 
edge  of  the  crevasse.  Balmat  came  forward  with  his  axe, 
and  tried  to  get  a  footing  on  the  eave  :  he  beat  it  gently, 
but  the  axe  went  through  the  snow,  forming  an  aperture 
through  which  the  darkness  of  the  chasm  was  rendered 
visible.  Our  guide  was  quite  free,  without  rope  or  any 
other  means  of  security  ;  he  beat  down  the  snow  so  as  to 
form  a  kind  of  stirrup,  and  upon  this  he  stepped.  The 
stirrup  gave  way,  it  was  right  over  the  centre  of  the 
chasm,  but  with  wonderful  tact  and  coolness  he  contrived 
to  get  sufficient  purchase  from  the  yielding  mass  to  toss 
himself  back  to  the  side  of  the  chasm.  The  rope  was 
now  brought  forward  and  tied  round  the  waist  of  one 
of  the  porters ;  another  step  was  cautiously  made  in 
the  eave  of  snow,  the  man  was  helped  across,  and  les- 
sened his  own  weight  by  means  of  his  hatchet.  He 
gradually  got  footing  pn  the  face  of  the  steep,  which  lie 
mounted  by  escaliers ;  and  on  reaching  a  sufficient  height 
he  cut  two  large  steps  in  which  his  feet  might  rest  se- 
curely. Here  he  laid  his  breast  against  the  sloping  wall, 
and  another  person  was  sent  forward,  who  drew  himself 
up  by  the  rope  which  was  attached  to  the  leader.  Thus 
we  all  passed,  each  of  us  in  turn  bearing  the  strain  of  his 


1858  ]  STORM  ON  MONT  BLANC.  189 

successor  upon  the  rope  ;  it  was  our  last  difficulty,  and 
we  afterwards  slowly  plodded  through  the  snow  of  the 
corridor  towards  the  base  of  the  Mur  de  la  Cote. 

Climbing  zigzag,  we  soon  reached  the  summit  of  the 
Mur,  and  immediately  afterwards  found  ourselves  in  the 
midst  of  cold  drifting  clouds,  which  obscured  everything. 
They  dissolved  for  a  moment  and  revealed  to  us  the 
sunny  valley  of  Chamouni ;  but  they  soon  swept  down 
again  and  completely  enveloped  us.  Upon  the  Calotte, 
or  last  slope,  I  felt  no  trace  of  the  exhaustion  which  I 
had  experienced  last  year,  but  enjoyed  free  lungs  and  a 
quiet  heart.  The  clouds  now  whirled  wildly  round  us, 
and  the  fine  snow,  which  was  caught  by  the  wind  and  spit 
bitterly  against  us,  cut  off  all  visible  communication  be- 
tween us  and  the  lower  world.  As  we  approached  the 
summit  the  air  thickened .  more  and  more,  and  the  cold, 
resulting  from  the  withdrawal  of  the  sunbeams,  became 
intense.  We  reached  the  top,  however,  in  good  condi- 
tion, and  found  the  new  snow  piled  up  into  a  sharp  arete, 
and  the  summit  of  a  form  quite  different  from  that  of 
the  Dos  (Tun  Ane,  which  it  had  presented  the  previous 
year.  Leaving  Balmat  to  make  a  hole  for  the  thermom- 
eter, I  collected  a  number  of  batons,  drove  them  into  the 
snow,  and,  drawing  my  plaid  around  them,  formed  a  kind 
of  extempore  tent  to  shelter  my  boiling-water  apparatus. 
The  covering  was  tightly  held,  but  the  snow  was  as  fine 
and  dry  as  dust,  and  penetrated  everywhere  :  my  lamp 
could  not  be  secured  from  it,  and  half  a  box  of  matches 
was  consumed  in  the  effort  to  ignite  it.  At  length  it 
did  flame  up,  and  carried  on  a  sputtering  combustion. 
The  cold  of  the  snow-filled  boiler,  condensing  the  vapour 
from  the  lamp,  gradually  produced  a  drop,  which,  when 
heavy  enough  to  detach  itself  from  the  vessel,  fell  upon  the 
flame  and  put  it  out.  It  required  much  patience  and  the 
expenditure  of  many  matches  to  relight  it.  Meanwhile 


190  THERMOMETER  BURIED.  [1858. 

the  absence  of  muscular  action  caused  the  cold  to  affect 
our  men  severely.  My  beard  and  whiskers  were  a  mass 
of  clotted  ice.  The  batons  were  coated  with  ice,  and  even 
the  stem  of  my  thermometer,  the  bulb  of  which  was  in 
hot  water,  was  covered  by  a  frozen  enamel.  The  clouds 
whirled,  and  the  little  snow  granules  hit  spitefully  against 
the  skin  wherever  it  was  exposed.  The  temperature  of 
the  air  was  20°  Fahr.  below  the  freezing  point.  I  was  too 
intent  upon  my  work  to  heed  the  cold  much,  but  I  was 
numbed  ;  one  of  my  fingers  had  lost  sensation,  and  my 
right  heel  was  in  pain :  still  I  had  no  thought  of  for- 
saking my  observation  until  Mr.  Wills  came  to  me  and 
said  that  we  must  return  speedily,  for  Balinat's  hands 
were  geUes.  I  did  not  comprehend  the  full  significance 
of  the  word  ;  but,  looking  at  the  porters,  they  presented 
such  an  aspect  of  suffering  that  I  feared  to  detain  them 
longer.  They  looked  like  worn  old  men,  their  hair  and 
clothing  white  with  snow,  and  their  faces  blue,  withered, 
and  anxious-looking.  The  hole  being  ready,  I  asked  Bal- 
rnat  for  the  magnet  to  arrange  the  index  of  the  thermom- 
eter :  his  hands  seemed  powerless.  I  struck  my  tent,  de- 
posited the  instrument,  and,  as  I  watched  the  covering  of 
it  up,  some  of  the  party,  among  whom  were  Mr.  Wills 
and  Balmat,  commenced  the  descent.* 

I  followed  them  speedily.  Midway  down  the  Calotte  I 
saw  Balmat,  who  was  about  a  hundred  yards  in  advance 
of  me,  suddenly  pause  and  thrust  his  hands  into  the  snow, 
and  commence  rubbing  them  vigorously.  The  sudden- 
ness of  the  act  surprised  me,  but  I  had  no  idea  at  the  time 
of  its  real  significance :  I  soon  came  up  to  him :  he  seemed 
frightened,  and  continued  to  beat  and  rub  his  hands, 
plunging  them,  at  quick  intervals,  into  the  snow.  Still 

*  In  August,  1859, 1  found  the  temperature  of  water,  boiling  in  an  open 
vessel  at  the  summit  of  Mont  Blanc,  to  be  184.95°  Fahr.  On  that  occasion, 
also,  though  a  laborious  search  was  made  for  the  thermometer,  it  could  not 
be  found. 


1858.]  BALMAT  FROSTBITTEN.  191 

I  thought  the  thing  would  speedily  pass  away,  for  I  had  too 
much  faith  in  the  man's  experience  to  suppose  that  he  would 
permit  himself  to  be  seriously  injured.  But  it  did  not  pass 
as  I  hoped  it  would,  and  the  terrible  possibility  of  his  losing 
his  hands  presented  itself  to  me.  He  at  length  became 
exhausted  by  his  own  efforts,  staggered  like  a  drunken 
man,  and  fell  upon  the  snow.  Mr.  Wills  and  myself  took 
each  a  hand,  and  continued  the  process  of  beating  and 
rubbing.  I  feared  that  we  should  injure  him  by  our  blows, 
but  he  continued  to  exclaim, "  N'ayez  pas  peur,  frappez  tou- 
jours,  frappez  fortement !  "  We  did  so,  until  Mr.  Wills 
became  exhausted,  and  a  porter  had  to  take  his  place. 
Meanwhile  Balmat  pinched  and  bit  his  fingers  at  inter- 
vals, to  test  their  condition  ;  but  there  was  no  sensation. 
He  was  evidently  hopeless  himself ;  and,  seeing  him  thus, 
produced  an  effect  upon  me  that  I  had  not  experienced 
since  my  boyhood,  —  my  heart  swelled,  and  I  could  have 
wept  like  a  child.  The  idea  that  I  should  be  in  some  mea- 
sure the  cause  of  his  losing  his  hands  was  horrible  to  me  ; 
schemes  for  his  support  rushed  through  my  mind  with  the 
usual  swiftness  of  such  speculations,  but  no  scheme  could 
restore  to  him  his  lost  hands.  At  length  returning  sensa- 
tion in  one  hand  announced  itself  by  excruciating  pain. 
"  Je  souifre  !  "  he  exclaimed  at  intervals,  —  words  which, 
from  a  man  of  his  iron  endurance,  had  a  more  than  ordinary 
significance.  But  pain  was  better  than  death,  and,  under 
the  circumstances,  a  sign  of  improvement.  We  resumed 
our  descent,  while  he  continued  to  rub  his  hands  with  snow 
and  brandy,  thrusting  them  at  every  few  paces  into  the 
mass  through  which  we  marched.  At  Chamouni  he  had 
skilful  medical  advice,  by  adhering  to  which  he  escaped 
with  the  loss  of  six  of  his  nails,  —  his  hands  were  saved. 

I  cannot  close  this  recital  without  expressing  my  ad- 
miration of  the  dauntless  bearing  of  our  porters,  and  of 
the  cheerful  and  efficient  manner  in  which  they  did  their 


192  PROOfcS   VERBAL.  [1858. 

duty  throughout  the  whole  expedition.  Their  names  are 
Edouard  Bellin,  Joseph  Favret,  Michel  Payot,  Joseph  Fol- 
liguet,  and  Alexandre  Balmat. 


(26.) 

THE  hostility  of  the  chief  guide  to  the  expedition  was 
not  diminished  by  the  letter  of  the  Intendant ;  and  he  at 
once  entered  a  proces  verbal  against  Balmat  and  his  com- 
panions on  their  return  to  Chamouni.  I  felt  that  the 
power  thus  vested  in  an  unlettered  man  to  arrest  the  pro- 
gress of  scientific  observations  was  so  anomalous,  that  the 
enlightened  and  liberal  Government  of  Sardinia  would 
never  tolerate  such  a  state  of  things  if  properly  represented 
to  it.  The  British  Association  met  at  Leeds  that  year,  and 
to  it,  as  a  guardian  of  science,  my  thoughts  turned.  I 
accordingly  laid  the  case  before  the  Association,  and  ob- 
tained its  support :  a  resolution  was  unanimously  passed, 
"  that  application  be  made  to  the  Sardinian  authorities  for 
increased  facilities  for  making  scientific  observations  in 
the  Alps." 

Considering  the  arduous  work  which  Balmat  had  per- 
formed in  former  years  in  connexion  with  the  glaciers,  and 
especially  his  zeal  in  determining,  under  the  direction  of 
Professor  Forbes,  their  winter  motion — for  which,  as  in  the 
case  above  recorded,  he  refused  all  personal  remuneration 
—  I  thought  such  services  worthy  of  some  recognition  on 
the  part  of  the  Royal  Society.  I  suggested  this  to  the 
Council,  and  was  met  by  the  same  cordial  spirit  of  co- 
operation which  I  had  previously  experienced  at  Leeds. 
A  sum  of  five-and-twenty  guineas  was  at  once  voted  for 
the  purchase  of  a  suitable  testimonial ;  and  a  committee, 
consisting  of  Sir  Roderick  Murchison,  Professor  Forbes, 


1858.]  BRITISH  ASSOCIATION.  193 

and  myself,  was  appointed  to  carry  the  thing  out.  Balniat 
was  consulted,  and  he  chose  a  photographic  apparatus, 
which,  with  a  suitable  inscription,  was  duly  presented  to 
him. 

Thus  fortified,  I  drew  up  an  account  of  what  had  occurred 
at  Chamouni  during  my  last  visit,  accompanied  by  a  brief 
statement  of  the  changes  which  seemed  desirable.  This 
was  placed  in  the  hands  of  the  President  of  the  British 
Association,  to  whose  prompt  and  powerful  co-operation  in 
this  matter  every  Alpine  explorer  who  aspires  to  higher 
ground  than  ordinary  is  deeply  indebted.  The  following 
letter  assured  me  that  the  facility  applied  for  by  the  British 
Association  would  be  granted  by  the  Sardinian  Govern- 
ment, and  that  future  men  of  science  would  find  in  the 
Alps  a  less  embarrassed  field  of  operations  than  had  fallen 
to  my  lot  in  the  summer  of  1858. 

"  1 2,  Hertford-street,  Mayfair,  W., 
"February  18th,  1859. 

"My  dear  Sir,— 

"  Having,  as  I  informed  you  in  my  last  note,  com- 
municated with  the  Sardinian  Minister  Plenipotentiary 
the  day  after  receiving  your  statement  relative  to  the 
guides  at  Chamouni,  I  have  been  favoured  by  replies  from 
the  Minister,  of  the  4th  and  17th  February.  In  the  first 
the  Marquis  d'Azeglio  assures  me  that  he  will  bring  the 
subject  before  the  competent  authorities  at  Turin,  accom- 
panying the  transmission  '  d'une  recommendation  toute 
speciale.'  In  the  second  letter  the  Marquis  informs  me 
that '  the  preparation  of  new  regulations  for  the  guides  at 
Chamouni  had  for  some  time  occupied  the  attention  of  the 
Minister  of  the  Interior,  and  that  these  regulations  will  be 
in  rigorous  operation,  in  all  probability,  at  the  commence- 
ment of  the  approaching  summer.'  The  Marquis  adds, 
that,  '  as  the  regulations  will  be  based  upon  a  principle  of 
much  greater  liberty,  he  has  every  reason  to  believe  that 
13 


194  THE  PEESIDENT'S  LETTER.  [1858. 

they  will  satisfy  all  the  desires  of  travellers  in  the  inter- 
ests of  science.7 

"  With  much  pleasure  at  the  opportunity  of  having  been 
in  any  degree  able  to  bring  about  the  fulfilment  of  your 
wishes  on  the  subject, 

"  I  remain,  my  dear  Sir,  faithfully  yours, 

"  RICHARD  OWEN, 
"  Pres.  Brit.  Association. 

"Prof.  Tyndall,  F.R.S." 

It  ought  to  be  stated,  that,  previous  to  my  arrival  at 
Chamouni  in  1858,  an  extremely  cogent  memorial  drawn 
up  by  Mr.  John  Ball  had  been  presented  to  the  Marquis 
d'Azeglio  by  a  deputation  from  the  Alpine  Club.  It  was 
probably  this  memorial  which  first  directed  the  attention 
of  the  Sardinian  Minister  of  the  Interior  to  the  subject. 


1859.]          FIRST  DEFEAT,   AND  FRESH  ATTEMPT.  195 


WINTER -EXPEDITION  TO  THE  HER  DE   GLACE, 

1859. 

(27.) 

HAVING  ten  days  at  my  disposal  last  Christmas,  I  was 
anxious  to  employ  them  in  making  myself  acquainted  with 
the  winter  aspects  and  phenomena  of  the  Mer  de  Glace. 
On  Wednesday,  the  21st  of  December,  I  accordingly  took 
my  place  to  Paris,  but  on  arriving  at  Folkestone  found  the 
sea  so  tempestuous  that  no  boat  would  venture  out. 

The  loss  of  a  single  day  was  more  than  I  could  afford, 
and  this  failure  really  involved  the  loss  of  two.  Seeing, 
therefore,  the  prospect  of  any  practical  success  so  small, 
I  returned  "to  London,  purposing  to  give  the  expedition 
up.  On  the  following  day,  however,  the  weather  lightened, 
and  I  started  again,  reaching  Paris  on  Friday  morning. 
On  that  day  it  was  not  possible  to  proceed  beyond  Macon, 
where,  accordingly,  I  spent  the  night,  and  on  the  follow- 
ing day  reached  Geneva. 

Much  snow  had  fallen ;  at  Paris  it  still  cumbered  the 
streets,  and  round  about  Macon  it  lay  thick,  as  if  a  more 
than  usually  heavy  cloud  had  discharged  itself  on  that 
portion  of  the  country.  Between  Macon  and  Roussillon 
it  was  lighter,  but  from  the  latter  station  onwards  the 
quantity  upon  the  ground  gradually  increased. 

On  Christmas  morning,  at  8  o'clock,  I  left  Geneva  by 
the  diligence  for  Sallenches.  The  dawn  was  dull,  but  the 
sky  cleared  as  the  day  advanced,  and  finally  a  dome  of 
cloudless  blue  stretched  overhead.  The  mountains  were 
grand  ;  their  sunward  portions  of  dazzling  whiteness, 
while  the  shaded  sides,  in  contrast  with  the  blue  sky 
behind  them,  presented  a  ruddy,  subjective  tint.  The 


196  GENEVA   TO   CHAMOUNI.  [1859. 

brightness  of  the  day  reached  its  maximum  towards  one 
o'clock,  after  which  a  milkiness  slowly  stole  over  the 
heavens,  and  increased  in  density  until  finally  a  drowsy 
turbidity  filled  the  entire  air.  The  distant  peaks  gradu- 
ally blended  with  the  white  atmosphere  above  them  and 
lost  their  definition.  The  black  pine  forests  on  the  slopes 
of  the  mountains  stood  out  in  strong  contrast  to  the  snow ; 
and,  when  looked  at  through  the  spaces  enclosed  by  the 
tree  branches  at  either  side  of  the  road,  they  appeared  of 
a  decided  indigo-blue.  It  was  only  when  thus  detached 
by  a  vista  in  front  that  the  blue  colour  was  well  seen,  the 
air  itself  between  the  eye  and  the  distant  pines  being  the 
seat  of  the  colour.  Goethe  would  have  regarded  it  as  an 
excellent  illustration  of  his  "  Farbenlehre." 

We  reached  Sallenches  a  little  after  4  P.  M.,  where  I  en- 
deavoured to  obtain  a  sledge  to  continue  my  journey.  A 
fit  one  was  not  to  be  found,  and  a  carriage  was  therefore 
the  only  resort.  We  started  at  five ;  it  was  very  dark, 
but  the  feeble  reflex  of  the  snow  on  each  side  of  the  road 
was  preferred  by  the  postilion  to  the  light  of  lamps.  Un- 
like the  enviable  ostrich,  I  cannot  shut  my  eyes  to  danger 
when  it  is  near :  and  as  the  carriage  swayed  towards  the 
precipitous  road-side,  I  could  not  fold  myself  up,  as  it 
was  intended  I  should,  but,  quitting  the  interior  and  divest- 
ing my  limbs  of  every  encumbrance,  I  took  my  seat  beside 
the  driver,  and  kept  myself  in  readiness  for  the  spring, 
which  in  some  cases  appeared  imminent.  My  companion, 
however,  was  young,  strong,  and  keen-eyed ;  and  though 
we  often  had  occasion  for  the  exercise  of  the  quality  last 
mentioned,  we  reached  Servoz  without  accident. 

Here  we  baited,  and  our  progress  afterwards  was  slow 
and  difficult.  The  snow  on  the  road  was  deep  and 
hummocky,  and  the  strain  upon  the  horses  very  great. 
Having  crossed  the  Arve  at  the  Pont-Pelissier,  we  both 
alighted,  and  I  went  on  in  advance.  The  air  was 


1859.]  DESOLATION.  197 

warm,  and  not  a  whisper  disturbed  its  perfect  repose. 
There  was  no  moon,  and  the  heavy  clouds,  which  now 
quite  overspread  the  heavens,  cut  off  even  the  feeble 
light  of  the  stars.  •  The  sound  of  the  Arve,  as  it  rushed 
through  the  deep  valley  to  my  left,  came  up  to  me 
through  crags  and  trees  with  a  sad  murmur.  Sometimes, 
on  passing  an  obstacle,  the  sound  was  entirely  cut  off, 
and  the  consequent  silence  was  solemn  in  the  extreme. 
It  was  a  churchyard  stillness,  and  the  tall  black  pines, 
which  at  intervals  cast  their  superadded  gloom  upon  the 
road,  seemed  like  the  hearse-plumes  of  a  dead  world.  I 
reached  a  wooden  hut,  where  a  lame  man  offers  batons, 
minerals,  and  eau  de  vie,  to  travellers  in  summer.  It  was 
forsaken,  and  half  buried  in  the  snow.  I  leaned  against 
the  door,  and  enjoyed  for  a  time  the  sternness  of  the  sur- 
rounding scene.  My  conveyance  was  far  behind,  and  the 
intermittent  tinkle  of  the  horses'  bells,  which  augmented 
instead  of  diminishing  the  sense  of  solitude,  informed  me 
of  the  progress  and  the  pauses  of  the  vehicle.  At  the 
summit  of  the  road  I  halted  until  my  companion  reached 
me ;  we  then  both  remounted,  and  proceeded  slowly  to- 
wards Les  Ouches.  We  passed  some  houses,  the  aspect 
of  which  was  even  more  dismal  than  that  of  Nature ;  their 
roofs  were  loaded  with  snow,  and  white  buttresses  were 
reared  against  the  walls.  There  was  no  sound,  no  light, 
no  voice  of  joy  to  indicate  that  it  was  the  pleasant  Christ- 
mas time.  We  once  met  the  pioneer  of  a  party  of  four 
drunken  peasants :  he  came  right  against  us,  and  the 
coachman  had  to  pull  up.  Planting  his  feet  in  the  snow 
and  propping  himself  against  the  leader's  shoulder,  the 
bacchanal  exhorted  the  postilion  to  drive  on  ;  the  latter 
took  him  at  his  word,  and  overturned  him  in  the  snow. 
After  this  we  encountered  no  living  thing.  The  horses 
seemed  seized  by  a  kind  of  torpor,  and  leaned  listlessly 
against  each  other ;  vainly  the  postilion  endeavoured  to 


198  A  HOKSE  IN  THE   SNOW.  [1859. 

rouse  them  by  word  and  whip  ;  they  sometimes  essayed 
to  trot  down  the  slopes,  but  immediately  subsided  to  their 
former  monotonous  crawl.  As  we  ascended  the  valley, 
the  stillness  of  the  air  was  broken  at  intervals  by  wild 
storm-gusts,  sent  down  against  us  from  Mont  Blanc  him- 
self. These  chilled  me,  so  I  quitted  the  carriage,  and 
walked  on;  Not  far  from  Chamouni,  the  road,  for  some 
distance,  had  been  exposed  to  the  full  action  of  the  wind, 
and  the  snow  had  practically  erased  it.  Its  left  wall  was 
completely  covered,  while  a  few  detached  stones,  rising 
here  and  there  above  the  surface,  were  the  only  indica- 
tions of  the  presence  and  direction  of  the  right-hand 
wall.  I  could  not  see  the  state  of  the  surface,  but  I 
learned  by  other  means  that  the  snow  had  been  heaped 
in  oblique  ridges  across  my  path.  I  staggered  over  four 
or  five  of  these  in  succession,  sinking  knee-deep,  and 
finally  found  myself  immersed  to  the  waist.  This  made 
me  pause ;  I  thought  I  must  have  lost  the  road,  and  vainly 
endeavoured  to  check  myself  by  the  positions  of  surround- 
ing objects.  I  turned  back  and  met  the  carriage  :  it  had 
stuck  in  one  of  the  ridges ;  one  horse  was  down,  his  hind 
legs  buried  to  the  haunches,  his  left  fore-leg  plunged  to 
the  shoulder  in  snow,  and  the  right  one  thrown  forward 
upon  the  surface.  C^est  bien  la  route  ?  demanded  my  com- 
panion. I  went  back  exploring,  and  assured  myself  that 
we  were  over  the  road  ;  but  I  recommended  him  to  release 
the  horses  and  leave  the  carriage  to  its  fate.  He,  however, 
succeeded  in  extricating  the  leader,  and  while  I  went  on 
in  advance  seeking  out  the  firmer  portions  of  the  road,  he 
followed,  holding  his  horses  by  their  heads  ;  and  half  an 
hour's  struggle  of  this  kind  brought  us  to  Chamouni. 

It  also  was  a  little  "  city  of  the  dead."  There  was  no  liv- 
ing thing  in  the  streets,  and  neither  sound  nor  light  in  the 
houses.  The  fountain  made  a  melancholy  gurgle,  one  or 
two  loosened  window-shutters  creaked  harshly  in  the  wind, 


1859.]  CHAMOUNI  ON  CHRISTMAS  NIGHT.  199 

and  banged  against  the  objects  which  limited  their  oscilla- 
tions. The  H6tel  de  PtJnion,  so  bright  and  gay  in  sum- 
mer, was  nailed  up  and  forsaken  ;  and  the  cross  in  front  of 
it,  stretching  its  snow-laden  arms  into  the.  dim  air,  was  the 
type  of  desolation.  We  rang  the  bell  at  the  H6tel  Royal, 
but  the  bay  of  a  watch-dog  resounding  through  the  house 
was  long  our  only  reply.  The  bell  appeared  powerless  to 
wake  the  sleepers,  and  its  sound  mingled  dismally  with 
that  of  the  wind  howling  through  the  deserted  passages. 
The  noise  of  my  boot-heel,  exerted  long  on  the  front  door, 
was  at  length  effective ;  it  was  unbarred,  and  the  physical 
heat  of  a  good  stove  soon  added  itself  to  the  warmth  of 
the  welcome  with  which  my  hostess  greeted  me. 

December  26th.  —  The  snow  fell  heavily,  at  frequent 
intervals,  throughout  the  entire  day.  Dense  clouds  draped 
all  the  mountains,  and  there  was  not  the  least  prospect  of 
my  being  able  to  see  across  the  Mer  de  Glace.  I  walked 
out  alone  in  the  dim  light,  and  afterwards  traversed  the 
streets  before  going  to  bed.  They  were  quite  forsaken. 
Cold  and  sullen  the  Arve  rolled  under  its  wooden  bridge, 
while  the  snow  fell  at  intervals  with  heavy  shock  from 
the  roofs  of  the  houses,  the  partial  echos  from  the  surfaces 
of  the  granules  combining  to  render  the  sound  loud  and 
hollow.  Thus  the  concerns  of  this  little  hamlet  were 
changed  and  fashioned  by  the  obliquity  of  the  earth's 
axis,  the  chain  of  dependence  which  runs  throughout 
creation,  linking  the  roll  of  a  planet  alike  with  the  in- 
terests of  marmots  and  of  men. 

Tuesday,  27th  December. — I  rose  at  six  o'clock,  having 
arranged  with  my  men  to  start  at  seven,  if  the  weather  at 
all  permitted.  Edouard  Simond,  my  old  assistant  of  1857, 
and  Joseph  Tairraz  were  the  guides  of  the  party ;  the 
porters  were  Edouard  Balmat,  Joseph  Simond  (fils  d'Au- 
guste),  Francois  Ravanal,  and  another.  They  came  at  the 
time  appointed  ;  it  was  snowing  heavily,  and  we  agreed  to 


200  ASCENT  OF  THE  MOUNTAIN.  [1859. 

wait  till  eight  o'clock  and  then  decide.  They  returned  at 
eight,  and  finding  them  disposed  to  try  the  ascent  to  the 
Montanvert,  it  was  not  my  place  to  baulk  them.  Through 
the  valley  the  work  was  easy,  as  the  snow  had  been  par- 
tially beaten  down,  but  we  soon  passed  the  habitable  limits, 
and  had  to  break  ground  for  ourselves.  Three  of  my  men 
had  tried  to  reach  the  Montanvert  by  la  Filia  on  the  pre- 
vious Thursday,  but  their  experience  of  the  route  had 
been  such  as  to  deter  them  from  trying  it  again.  We 
now  chose  the  ordinary  route,  breasting  the  slope  until  we 
reached  the  cluster  of  chalets,  under  the  projecting  eave 
of  one  of  which  the  men  halted  and  applied  "  pattens  "  to 
their  feet.  These  consisted  of  planks  about  sixteen  inches 
long  and  ten  wide,  which  were  firmly  strapped  to  the  feet. 
My  first  impression  was  that  they  were  worse  than  useless, 
for  though  they  sank  less  deeply  than  the  unarmed  feet, 
on  being  raised  they  carried  with  them  a  larger  amount 
of  snow,  which,  with  the  leverage  of  the  leg,  appeared  to 
necessitate  an  enormous  waste  of  force.  I  stated  this 
emphatically,  but  the  men  adhered  to  their  pattens,  and 
before  I  reached  the  Montanvert  I  had  reason  to  commend 
their  practice  as  preferable  to  my  theory.  I  was,  however, 
guided  by  the  latter,  and  wore  no  pattens.  The  general 
depth  of  the  snow  along  the  track  was  over  three  feet ;  the 
footmarks  of  the  men  were  usually  rigid  enough  to  bear 
my  weight,  but  in  many  cases  I  went  through  the  crust 
which  their  pressure  had  produced,  and  sank  suddenly 
in  the  mass.  The  snow  became  softer  as  we  ascended, 
and  my  immersions  more  frequent,  but  the  work  was 
pure  enjoyment,  and  the  scene  one  of  extreme  beauty. 
The  previous  night's  snow  had  descended  through  a  per- 
fectly still  atmosphere,  and  had  loaded  all  the  branches 
of  the  pines  ;  the  long  arms  of  the  trees  drooped  under 
the  weight,  and  presented  at  their  extremities  the  ap- 
pearance of  enormous  talons  turned  downwards.  Some 


1859.]  SNOW  ON  THE  PINES.  201 

of  the  smaller  and  thicker  trees  were  almost  entirely  cov- 
ered, and  assumed  grotesque  and  beautiful  forms  ;  the 
upper  part  of  one  in  particular  resembled  a  huge  white 
parrot  with  folded  wings  and  drooping  head,  the  slumber 
of  the  bird  harmonizing  with  the  torpor  of  surrounding 
nature.  I  have  given  a  sketch  of  it  in  Fig.  13. 


Fig.  13. 

Previous  to  reaching  the  half-way  spring,  where  the 
peasant-girls  offer  strawberries  to  travellers  in  summer, 
we  crossed  two  large  couloirs  filled  with  the  debris  of 
avalanches  which  had  fallen  the  night  before.  Between 
these  was  a  ridge  forty  or  fifty  yards  wide  on  which  the 
snow  was  very  deep,  the  slope  of  the  mountain  also  add- 
ing a  component  to  the  fair  thickness  of  the  snow.  My 
shoulder  grazed  the  top  of  the  embankment  to  my  right 
as  I  crossed  the  ridge,  and  once  or  twice  I  found  myself 
waist  deep  in  a  vertical  shaft  from  which  it  required  a  con- 


202  SOUND  OF  BREAKING   SNOW.  [1859. 

siderable  effort  to  escape.  Suddenly  we  heard  a  deep  sound 
resembling  the  dull  report  of  a  distant  gun,  and  at  the  same 
moment  the  snow  above  us  broke  across,  forming  a  fissure 
parallel  to  our  line  of  march.  The  layer  of  snow  had  been 
in  a  state  of  strain,  which  our  crossing  brought  to  a  crisis  : 
it  gave  way,  but  having  thus  relieved  itself  it  did  not  de- 
scend. Several  times  during  the  ascent  the  same  pheno- 
menon occurred.  Once,  while  engaged  upon  a  very  steep 
slope,  one  of  the  men  cried  out  to  the  leader,  "Arretez!  " 
Immediately  in  front  of  the  latter  the  snow  had  given  way, 
forming  a  zigzag  fissure  across  the  slope.  We  all  paused,, 
expecting  to  see  an  avalanche  descend.  Tairraz  was  in 
front ;  he  struck  the  snow  with  his  baton  to  loosen  it,  but 
seeing  it  indisposed  to  descend,  he  advanced  cautiously 
across  it,  and  was  followed  by  the  others.  I  brought  up 
the  rear.  The  steepness  of  the  mountain-side  at  this 
place,  and  the  absence  of  any  object  to  which  one  might 
cling,  would  have  rendered  a  descent  with  the  snow  in  the 
last  degree  perilous,  and  we  all  felt  more  at  ease  when  a 
safe  footing  was  secured  at  the  further  side  of  the  incline. 
At  the  spring,  which  showed  a  little  water,  the  men 
paused  to  have  a  morsel  of  bread.  The  wind  had  changed, 
the  air  was  clearing,  and  our  hopes  brightening.  As  we 
ascended,  the  atmosphere  went  through  some  extraordi- 
nary mutations.  Clouds  at  first  gathered  round  the  Ai- 
guille and  Dome  du  Goute,  casting  the  lower  slopes  of  the 
mountain  into  intense  gloom.  After  a  little  time  all  this 
cleared  away,  and  the  beams  of  the  sun  striking  detached 
pieces  of  the  slopes  and  summits  produced  an  extraor- 
dinary effect.  The  Aiguille  and  D6me  were  most  singu- 
larly illumined,  and  to  the  extreme  left  rose  the  white 
conical  hump  of  the  Dromedary,  from  which  a  long 
streamer  of  snow-dust  was  carried  southward  by  the  wind. 
The  Aiguille  du  Dru,  which  had  been  completely  mantled 
during  the  earlier  part  of  the  day,  now  threw  off  its  cloak 


1859.]  COLOUR  OF  SNOW.  203 

of  vapour  and  rose  in  most  solemn  majesty  before  us ; 
half  of  its  granite  cone  was  warmly  illuminated,  and 
half  in  shadow.  The  wind  was  high  in  the  upper  regions, 
and,  catching  the  dry  snow  which  rested  on  the  asperities 
and  ledges  of  the  Aiguille,  shook  it  out  like  a  vast  ban- 
ner in  the  air.  The  changes  of  the  atmosphere,  and  the 
grandeur  which  they  by  turns  revealed  and  concealed, 
deprived  the  ascent  of  all  weariness.  We  were  usually 
flanked  right  and  left  by  pines,  but  once  between  the 
fountain  and  the  Montanvert  we  had  to  cross  a  wide  un- 
sheltered portion  of  the  mountain  which  was  quite  cov- 
ered with  the  snow  of  recent  avalanches.  This  was  lumpy 
and  far  more  coherent  than  the  undisturbed  snow.  We 
took  advantage  of  this,  and  climbed  zigzag  over  the 
avalanches  for  three  quarters  of  an  hour,  thus  reaching 
the  opposite  pines  at  a  point  considerably  higher  than  the 
path.  This,  though  not  the  least  dangerous,  was  the 
least  fatiguing  part  of  the  ascent. 

I  frequently  examined  the  colour  of  the  snow :  though 
fresh,  its  blue  tint  was  by  no  means  so  pronounced  as  I 
have  seen  it  on  other  occasions  ;  still  it  was  beautiful. 
The  colour  is,  no  doubt,  due  to  the  optical  reverbera- 
tions which  occur  within  a  fissure  or  cavity  formed  in 
the  snow.  The  light  is  sent  from  side  to  side,  each  time 
plunging  a  little  way  into  the  mass  ;  and  being  ejected 
from  it  by  reflection,  it  thus  undergoes  a  sifting  process, 
and  finally  reaches  the  eye  as  blue  light.  The  presence 
of  any  object  which  cuts  off  this  cross-fire  of  the  light 
destroys  the  colour.  I  made  conical  apertures  in  the 
snow,  in  some  cases  three  feet  deep,  a  foot  wide  at  the 
mouth,  and  tapering  down  to  the  width  of  my  baton. 
When  the  latter  was  placed  along  the  axis  of  such  a 
cone,  the  blue  light  which  had  previously  filled  the  cavity 
disappeared ;  on  the  withdrawal  of  the  baton  it  was  fol- 
lowed by  the  light,  and  thus,  by  moving  the  staff  up  and 


204  THE  MONTANVERT  IN  WINTER.  [1859. 

down,  its  motions  were  followed  by  the  alternate  appear- 
ance and  extinction  of  the  light.  I  have  said  that  the 
holes  made  in  the  snow  seemed  filled  with  a  blue  light, 
and  it  certainly  appeared  as  if  the  air  contained  in  the 
cavities  had  itself  been  coloured,  and  thereby  rendered 
visible,  the  vision  plunging  into  it  as  into  a  blue  medium. 
Another  fact  is  perhaps  worth  notice  :  snow  rarely  lies  so 
smooth  as  not  to  present  little  asperities  at  the  surface  ; 
little  ridges  or  hillocks,  with  little  hollows  between  them. 
Such  small  hollows  resemble,  in  some  degree,  the  cavities 
which  I  made  in  the  snow,  and  from  them,  in  the  present 
instance,  a  delicate  light  was  sent  to  the  eye,  faintly 
tinted  with  the  pure  blue  of  the  snow-crystals.  In  com- 
parison with  the  spots  thus  illuminated,  the  little  pro- 
tuberances were  gray.  The  portions  most  exposed  to  the 
light  seemed  least  illuminated,  and  their  defect  in  this 
respect  made  them  appear  as  if  a  light-brown  dust  had 
been  strewn  over  them. 

After  five  hours  and  a  half  of  hard  work  we  reached  the 
Montanvert.  I  had  often  seen  it  with  pleasure.  Often, 
having  spent  the  day  alone  amid  the  seracs  of  the  Col  du 
Ge'ant,  on  turning  the  promontory  of  Trelaporte  on  my 
way  home,  the  sight  of  the  little  mansion  has  gladdened 
me,  and  given  me  vigour  to  scamper  down  the  glacier, 
knowing  that  pleasant  faces  and  wholesome  fare  were 
awaiting  me.  This  day,  also,  the  sight  of  it  was  most 
welcome,  despite  its  desolation.  The  wind  had  swept 
round  the  auberge,  and  carried  away  its  snow-buttresses, 
piling  the  mass  thus  displaced  against  the  adjacent  sheds, 
to  the  roofs  of  which  one  might  step  from  the  surface  of 
the  snow.  The  floor  of  the 'little  chateau  in  which  I 
lodged  in  1857  was  covered  with  snow,  and  on  it  were  the 
fresh  footmarks  of  a  little  animal  —  a  marmot  might  have 
made  such  marks,  had  not  the  marmots  been  all  asleep  — 
what  the  creature  was,  I  do  not  know. 


1859.]  CRYSTAL   CURTAIN.  205 

In  the  application  of  her  own  principles,  Nature  often 
transcends  the  human  imagination;  her  acts  are  bolder 
than  our  predictions.  It  is  thus  with  the  motion  of  glaciers ; 
it  was  thus  at  the  Montanvert  on  the  day  now  referred  to. 
The  floors,  even  where  the  windows  appeared  well  closed, 
were  covered  with  a  thin  layer  of  fine  snow ;  and  some  of 
the  mattresses  in  the  bedrooms  were  coated  to  the  depth 
of  half  an  inch  with  this  fine  powder.  Given  a  chink 
through  which  the  finest  dust  can  pass,  dry  snow  appears 
competent  to  make  its  way  through  the  same  fissure.  It 
had  also  been  beaten  against  the  windows,  and  clung  there 
like  a  ribbed  drapery.  In  one  case  an  effect  so  singular 
was  exhibited,  that  I  doubted  my  eyes  when  I  first  saw  it. 
In  front  of  a  large  pane  of  glass,  and  quite  detached 
from  it,  save  at  its  upper  edge,  was  a  festooned  curtain 
formed  entirely  of  minute  ice  crystals.  It  appeared  to  be 
as  fine  as  muslin  ;  the  ease  of  its  curves  and  the  depth 
of  its  folds  being  such  as  could  not  be  excelled  by  the 
intentional  arrangement  of  ordinary  gauze.  The  frost- 
figures  on  some  of  the  window-panes  were  also  of  the  most 
extraordinary  character :  in  some  cases  they  extended 
over  large  spaces,  and  presented  the  appearance  which  we 
often  observe  in  London  ;  but  on  other  panes  they  oc- 
curred in  detached  clusters,  or  in  single  flowers,  these 
grouping  themselves  together  to  form  miniature  bouquets 
of  inimitable  beauty.  I  placed  my  warm  hand  against 
a  pane  which  was  covered  by  the  crystallization,  and 
melted  the  frostwork  which  clung  to  it.  I  then  withdrew 
my  hand  and  looked  at  the  film  of  liquid  through  a  pocket- 
lens.  The  glass  cooled  by  contact  with  the  air,  and  after 
a  time  the  film  commenced  to  move  at  one  of  its  edges  ; 
atom  closed  with  atom,  and  the  motion  ran  in  living  lines 
through  the  pellicle,  until  finally  the  entire  film  presented 
the  beauty  and  delicacy  of  an  organism.  The  connexion 
between  such  objects  and  what  we  are  accustomed  to 


206  THE   MER  DE   GLACE  IN  WINTER.  [1859. 

call  the  feelings  may  not  be  manifest,  but  it  is  neverthe- 
less true  that,  besides  appealing  to  the  pure  intellect  of 
man,  these  exquisite  productions  can  also  gladden  his 
heart  and  moisten  his  eyes. 

The  glacier  excited  the  admiration  of  us  all :  not  as  in 
summer,  shrunk  and  sullied  like  a  spent  reptile,  steaming 
under  the  influence  of  the  sun,  its  frozen  muscles  were 
compact ;  strength  and  beauty  were  associated  in  its  as- 
pect. At  some  places  it  was  pure  and  smooth  ;  at  others 
frozen  fins  arose  from  it,  high,  steep,  and  sharply  crest- 
ed. Down  the  opposite  mountain-side  arrested  streams 
set  themselves  erect  in  successive  terraces,  the  fronts  of 
which  were  fluted  pillars  of  ice.  There  was  no  sound  of 
water  ;  even  the  Nant  Blanc,  which  gushes  from  a  spring, 
and  which  some  describe  as  permanent  throughout  the  win- 
ter, showed  no  trace  of  existence.  From  the  Montanvert 
to  Trelaporte  the  Mer  de  Glace  was  all  in  shadow ;  but 
the  sunbeams  pouring  down  the  corridor  of  the  Ge*ant 
ruled  a  beam  of  light  across  the  glacier  at  its  upper  por- 
tion, smote  the  base  of  the  Aiguille  du  Moine,  and  flooded 
the  mountain  with  glory  to  its  crest.  At  the  opposite  side 
of  the  valley  was  the  Aiguille  du  Dru,  with  a  banneret 
of  snow  streaming  from  its  mighty  cone.  The  Grande 
Jorasse,  and  the  range  of  summits  between  it  and  the 
Aiguille  du  Ge*ant,  were  all  in  view,  and  the  Charmoz 
raised  its  precipitous  cliffs  to  the  right,  and  pierced  with 
its  splinter-like  pinnacles  the  clear  cold  air.  As  the  night 
drew  on,  the  mountains  seemed  to  close  in  upon  us  ;  and 
on  looking  out  before  retiring  to  rest,  a  scene  so  solemn 
had  never  before  presented  itself  to  my  eyes  or  aifected 
my  imagination. 

My  men  occupied  the  afternoon  of  the  day  of  our 
arrival  in  making  a  preliminary  essay  upon  the  glacier 
while  I  prepared  my  instruments.  To  the  person  whom 
I  intended  to  fix  my  stations,  three  others  were  at- 


1859.]  THE  FIRST  NIGHT.  207 

tached  by  sound  ropes  of  considerable  length.  Hidden 
crevasses  we  knew  were  to  be  encountered,  and  we  had 
made  due  preparation  for  them.  Throughout  the  after- 
noon the  weather  remained  fine,  and  at  night  the  stars 
shone  out,  but  still  with  a  feeble  lustre.  I  could  notice  a 
turbidity  gathering  in  the  air  over  the  range  of  the  Bre*- 
vent,  which  seemed  disposed  to  extend  itself  towards  us. 
At  night  I  placed  a  chair  in  the  middle  of  the  snow,  at 
some  distance  from  the  house,  and  laid  on  it  a  registering 
thermometer.  A  bountiful  fire  of  pine  logs  was  made  in 
the  salle  a  manger ;  a  mattress  was  placed  with  its  foot 
towards  the  fire,  its  middle  line  bisecting  the  right  angle 
in  which  the  fireplace  stood  ;  this  being  found  by  experi- 
ment to  be  the  position  in  which  the  drafts  from  the  door 
and  from  the  windows  most  effectually  neutralized  each 
other.  In  this  region  of  calms  I  lay  down,  and  covering 
myself  with  blankets  and  duvets,  listened  to  the  crackling 
of  the  logs,  and  watched  their  ruddy  flicker  upon  the 
walls,  until  I  fell  asleep. 

The  wind  rose  during  the  night,  and  shook  the  win- 
dows :  one  pane  in  particular  seemed  set  in  unison  to  the 
gusts,  and  responded  to  them  by  a  loud  and  melodious 
vibration.  I  rose  and  wedged  it  round  with  sous  and 
penny  pieces,  and  thus  quenched  its  untimely  music. 

December  28th.  —  We  were  up  before  the  dawn. 
Tairraz  put  my  fire  in  order,  and  I  then  rose.  The  tem- 
perature of  the  room  at  a  distance  of  eight  feet  from  the 
fire  wa"s  two  degrees  of  Centigrade  below  zero ;  the  lowest 
temperature  outside  was  eleven  degrees  of  Centigrade  be- 
low zero,  —  not  at  all  an  excessive  cold.  The  clouds  in- 
deed had,  during  the  night,  thrown  vast  diaphragms  across 
the  sky,  and  thus  prevented  the  escape  of  the  earth's  heat 
into  space. 

While  my  assistants  were  preparing  breakfast  I  had 
time  to  inspect  the  glacier  and  its  bounding  heights.  On 


208  A  "ROSE   OF  DAWN."  [1858. 

looking  up  the  Mer  de  Glace,  the  Grande  Jorasse  meets 
the  view,  rising  in  steep  outline  from  the  wall  of  cliffs 
which  terminates  the  Glacier  de  Le*chaud.  Behind  this 
steep  ascending  ridge,  which  is  shown  on  the  frontis- 
piece, and  upon  it,  a  series  of  clouds  had  ranged  them- 
selves, stretching  lightly  along  the  ridge  at  some  places, 
and  at  others  collecting  into  ganglia.  A  string  of  rosettes 
was  thus  formed  which  were  connected  together  by  gauzy 
filaments.  The  portion  of  the  heavens  behind  the  ridge 
was  near  the  domain  of  the  rising  sun,  and  when  he 
cleared  the  horizon  his  red  light  fell  upon  the  clouds,  and 
ig*nited  them  to  ruddy  flames.  Some  of  the  lighter  clouds 
doubled  round  the  summit  of  the  mountain,  and  swathed 
its  black  crags  with  a  vestment  of  transparent  red.  The 
adjacent  sky  wore  a  strange  and  supernatural  air;  indeed, 
there  was  something  in  the  whole  scene  which  baffled 
analysis,  and  the  words  of  Tennyson  rose  to  my  lips  as  I 
gazed  upon  it :  — 

"  God  made  Himself  an  awful  rose  of  dawn." 

I  have  spoken  several  times  of  the  cloud-flag  which 
the  wind  wafted  from  the  summit  of  the  Aigirille  du  Dru. 
On  the  present  occasion  this  grand  banner  reached  ex- 
traordinary dimensions.  It  was  brindled  in  some  places 
as  if  whipped  into  curds  by  the  wind ;  but  through  these 
continuous  streamers  were  drawn,  which  were  bent  into 
sinuosities  resembling  a  waving  flag  at  a  mast-head.  All 
this  was  now  illuminated  with  the  sun's  red  rays,* which 
also  fringed  with  fire  the  exposed  edges  and  pinnacles 
both  of  the  Aiguille  du  Dru  and  the  Aiguille  Yerte.  Thus 
rising  out  of  the  shade  of  the  valley  the  mountains  burned 
like  a  pair  of  torches,  the  flames  of  which  were  blown  half 
a  mile  through  the  air.  Soon  afterwards  the  summits  of 
the  Aiguilles  Rouges  were  illuminated,  and  day  declared 
itself  openly  among  the  mountains. 


1359.]  THE  STAKES  FIXED.  209 

But  these  red  clouds  of  the  morning,  magnificent 
though  they  were,  suggested  thoughts  which  tended  to 
qualify  the  pleasure  which  they  gave :  they  did  not  indi- 
cate good  weather.  Sometimes,  indeed,  they  had  to  fight 
with  denser  masses,  which  often  prevailed,  swathing  the 
mountains  in  deep  neutral  tint,  but  which,  again  yielding, 
left  the  glory  of  the  sunrise  augmented  by  contrast  with 
their  gloom.  Between  eight  and  nine  A.  M.  we  commenced 
the  setting  out  of  our  first  line,  one  of  whose  termini  was  a 
point  about  a  hundred  yards  higher  up  than  the  Montanvert 
hotel ;  a  withered  pine  on  the  opposite  mountain-side  mark- 
ing the  other  terminus.  The  stakes  made  use  of  were  four 
feet  long.  With  the  selfsame  baton  which  I  had  employed 
upon  the  Mer  de  Glace  in  1857,  and  which  Simond  had  pre- 
served, the  worthy  fellow  now  took  up  the  line.  At  some 
places  the  snow  was  very  deep,  but  its  lower  portions  were 
sufficiently  compact  to  allow  of  a  stake  being  firmly  fixed  in 
it.  At  those  places  where  the  wind  had  removed  the  snow 
or  rendered  it  thin,  the  ice  was  pierced  with  an  auger 
and  the  stake  driven  into  it.  The  greatest  caution  was 
of  course  necessary  on  the  part  of  the  men ;  they  were  in 
the  midst  of  concealed  crevasses,  and  sounding  was  essen- 
tial at  every  step.  By  degrees  they  withdrew  from  me, 
and  approached  the  eastern  boundary  of  the  glacier,  where 
the  ice  was  greatly  dislocated,  and  the  labour  of  wading 
through  the  snow  enormous.  Long  devours  were  some- 
times necessary  to  reach  a  required  point ;  but  they  were  all 
accomplished,  and  we  at  length  succeeded  in  fixing  eleven 
stakes  along  this  line,  the  most  distant  of  which  was  within 
about  eighty  yards  of  the  opposite  side  of  the  glacier. 

The  men  returned,  and  I  consulted  them  as  to  the  pos- 
sibility of  getting  a  line  across  at  the  Fonts  ;  but  this  was 
judged  to  be  impossible  in  the  time.  We  thought,  however, 
that  a  second  line  might  be  staked  out  at  some  distance 
below  the  Montanvert.  I  took  the  theodolite  down  the 
14 


210  STORM  ON  THE  GLACIER.  [1859. 

mountain-slope,  wading  at  times  breast  deep  in  snow,  and 
having  selected  a  line,  the  men  tied  themselves  together 
as  before,  and  commenced  the  staking  out.  The  work 
was  slowly,  but  steadily  and  steadfastly  done.  The  air 
darkened  ;  angry  clouds  gathered  around  the  moun- 
tains, and  at  times  the  -glacier  was  swept  by  wild 
squalls.  The  men  were  sometimes  hidden  from  me  by 
the  clouds  of  snow  which  enveloped  them,  but  between 
those  intermittent  gusts  there  were  intervals  of  repose, 
which  enabled  us  to  prosecute  our  work.  This  line  was 
more  difficult  than  the  first  one  ;  the  glacier  was  broken 
into  sharp-edged  chasms ;  the  ridges  to  be  climbed  were 
steep,  and  the  snow  which  filled  the  depressions  pro- 
found. The  oblique  arrangement  of  the  crevasses  also 
magnified  the  labour  by  increasing  the  circuits.  I  saw  the 
leader  of  the  party  often  shoulder-deep  in  snow,  treading  the 
soft  mass  as  a  swimmer  walks  in  water,  and  I  felt  a  wish 
to  be  at  his  side  to  cheer  him  and  to  share  his  toil.  Each 
man  there,  however,  knew  my  willingness  to  do  this  if 
occasion  required  it,  and  wrought  contented.  At  length, 
the  last  stake  being  fixed,  the  faces  of  the  men  were 
turned  homeward.  The  evening  became  wilder,  and  the 
storm  rose  at  times  to  a  hurricane.  On  the  more  level 
portions  of  the  glacier  the  snow  lay  deep  and  unshel- 
tered ;  among  its  frozen  waves  and  upon  its  more  dislo- 
cated portions  it  had  been  partially  engulfed,  and  the 
residue  was  more  or  less  in  shelter.  Over  the  former 
spaces  dense  clouds  of  snow  rose,  whirling  in  the  air  and 
cutting  off  all  view  of  the  glacier.  The  whole  length  of 
the  Mer  de  Glace  was  thus  divided  into  clear  and  cloudy 
segments,  and  presented  an  aspect  of  wild  and  wonderful 
turmoil.  A  large  pine  stood  near  me,  with  its  lowest 
branch  spread  out  upon  the  surface  of  the  snow  ;  on  this 
branch  I  seated  myself,  and,  sheltered  by  the  trunk,  waited 
until  I  saw  my  men  in  safety.  The  wind  caught  the 


1859]  HEAVY  SNOW.  211 

branches  of  the  trees,  shook  down  their  loads  of  snow, 
and  tossed  it  wildly  in  the  air.  Every  mountain  gave  a 
quota  to  the  storm.  The  scene  was  one  of  most  im- 
pressive grandeur,  and  the  moan  of  the  adjacent  pines 
chimed  in  noble  harmony  with  the  picture  which  ad- 
dressed the  eyes. 

At  length  we  all  found  ourselves  in  safety  within  doors. 
The  windows  shook  violently.  The  tempest  was  however 
intermittent  throughout,  as  if  at  each  effort  it  had  ex- 
hausted itself,  and  required  time  to  recover  its  strength. 
As  I  heard  its  heralding  roar  in  the  gullies  of  the  moun- 
tains, and  its  subsequent  onset  against  our  habitation,  I 
thought  wistfully  of  my  stations,  not  knowing  whether 
they  would  be  able  to  retain  their  positions  in  the  face  of 
such  a  blast.  That  night,  however,  as  if  the  storm  had 
sung  our  lullaby,  we  all  slept  profoundly,  having  arranged 
to  commence  our  measurements  as  early  as  light  permitr 
ted  on  the  following  day. 

Thursday,  29th  December.  —  "Snow,  heavy  snow:  it 
must  have  descended  throughout  the  entire  night,  the 
quantity  freshly  fallen  is  so  great ;  the  atmosphere  at 
seven  o'clock  is  thick  with  the  descending  flakes."  At 
eight  o'clock  it  cleared  up  a  little,  and  I  proceeded  to  my 
station,  while  the  men  advanced  upon  the  glacier  ;  but  I 
had  scarcely  fixed  my  theodolite  when  the  storm  recom- 
menced. I  had  a  man  to  clear  away  the  snow  and  other- 
wise assist  me  ;  he  procured  an  old  door  from  the  hotel, 
and  by  rearing  it  upon  its  end  sheltered  the  object-glass 
of  the  instrument.  Added  to  the  flakes  descending  from 
the  clouds  was  the  spitting  snow-dust  raised  by  the  wind, 
which  for  a  time  so  blinded  me  that  I  was  unable  to  see 
the  glacier.  The  measurement  of  the  first  stake  was  very 
tedious,  but  practice  afterwards  enabled  me  to  take  ad- 
vantage of  the  brief  lulls  and  periods  of  partial  clearness 
with  which  the  storm  was  interfused. 


212  A  MAN  IN  A  'CREVASSE.  [1359. 

At  nine  o'clock  my  telescope  happened  to  be  directed 
upon  the  men  as  they  struggled  through  the  snow ;  all 
evidence  of  the  deep  track  which  they  had  formed  yes- 
terday having  been  swept  away.  I  saw  the  leader  sink 
and  suddenly  disappear.  He  had  stood  over  a  concealed 
fissure,  the  roof  of  which  had  given  way  and  he  had 
dropped  in.  I  observed  a  rapid  movement  on  the  part 
of  the  remaining  three  men  :  they  grouped  themselves 
beside  the  fissure,  and  in  a  moment  the  missing  man  was 
drawn  from  between  its  jaws.  His  disappearance  and 
appearance  were  both  extraordinary.  We  had,  as  I  have 
stated,  provided  for  contingencies  of  this  kind,  and  the 
man's  rescue  was  almost  immediate. 

My  attendant  brought  two  poles  from  the  hotel  which 
we  thrust  obliquely  into  the  snow,  causing  the  free  ends 
to  cross  each  other  ;  over  these  a  blanket  was  thrown,  be- 
hind which  I  sheltered  myself  from  the  storm  as  the  men 
proceeded  from  stake  to  stake.  At  9.30  the  storm  was  so 
thick  that  I  was  unable  to  see  the  men  at  the  stake  which 
they  had  reached  at  the  time ;  the  flakes  sped  wildly  in 
their  oblique  course  across  the  field  of  the  telescope. 
Some  time  afterwards  the  air  became  quite  still,  and  the 
snow  underwent  a  wonderful  change.  Frozen  flowers 
similar  to  those  I  had  observed  on  Monte  Rosa  fell  in 
myriads.  For  a  long  time  the  flakes  were  wholly  com- 
posed of  these  exquisite  blossoms  entangled  together.  On 
the  surface  of  my  woollen  dress  they  were  soft  as  down  ; 
the  snow  itself  on  which  they  fell  seemed  covered  by  a  layer 
of  down  ;  while  my  coat  was  completely  spangled  with 
six-rayed  stars.  And  thus  prodigal  Nature  rained  down 
beauty,  and  had  done  so  here  for  ages  unseen  by  man. 
And  yet  some  flatter  themselves  with  the  idea  that  this 
world  was  planned  with  strict  reference  to  human  use;  that 
the  lilies  of  the  field  exist  simply  to  appeal  to  the  sense  of 
the  beautiful  in  man.  True,  this  result  is  secured,  but  it 


1859.]  SIX-RAYED   CRYSTALS.  213 

is  one  of  a  thousand  all  equally  important  in  the  eyes  of 
Nature.  Whence  those  frozen  blossoms  ?  Why  for  JEons 
wasted  ?  The  question  reminds  one  of  the  poet's  answer 
when  asked  whence  was  the  Rhodora  :  — 

"  Why  wert  thou  there,  O  rival  of  the  rose  ? 

I  never  thought  to  ask,  I  never  knew ; 
But  in  my  simple  ignorance  suppose 

The  selfsame  power  that  brought  me  there  brought  you  ! "  * 

I  sketched  some  of  the  crystals,  but,  instad  of  repro- 
ducing these  sketches,  which  were  rough  and  hasty,  I 
have  annexed  two  of  the  forms  drawn  with  so  much  skill 
and  patience  by  Mr.  Glaisher. 

We  completed  the  measurement  of  the  first  line  before 
eleven  o'clock,  and  I  felt  great  satisfaction  in  the  thought 
that  I  possessed  something  of  which  the  weather  could 
not  deprive  me.  As  I  closed  my  note-book  and  shifted 
the  instrument  to  the  second  station,  I  felt  that  my  expe- 
dition was  already  a  success. 

At  a  quarter  past  eleven  I  had  my  theodolite  again 
fixed,  and,  ranging  the  telescope  alone  the  line  of  pickets, 
I  saw  them  all  standing.  Crossing  the  ice  wilderness,  and 
suggesting  the  operation  of  intelligence  amid  that  scene 
of  desolation,  their  appearance  was  pleasant  to  me.  Just 
before  I  commenced,  a  solitary  jay  perched  upon  the 
summit  of  an  adjacent  pine  and  watched  me.  The  air 
was  still  at  the  time,  and  the  snow  fell  heavily.  The  flow- 
ers moreover  were  magnificent,  varying  from  about  the 
twentieth  of  an  inch  to  two  lines  in  diameter,  while,  falling 
through  the  quiet  air,  their  forms  were  perfect.  Adjacent 
to  my  theodolite  was  a  stump  of  pine,  from  which  I  had 
the  snow  removed,  in  order  to  have  something  to  kick  my 
toes  against  when  they  became  cold  ;  and  on  the  stump 
was  placed  a  blanket  to  be  used  as  a  screen  in  case  of  need. 
While  I  remained  at  the  station  a  layer  of  snow  an  inch 

*  Emerson. 


Fig.  J4. 


Fig.  15. 


1859.]  SOUND  THROUGH  THE   SNOW-STORM.  215 

thick  fell  upon  this  blanket,  the  whole  layer  being  com- 
posed of  these  exquisite  flowers.  The  atmosphere  also  was 
filled  with  them.  From  the  clouds  to  the  earth  Nature  was 
busy  marshalling  her  atoms,  and  putting  to  shame  by  the 
beauty  of  her  structures  the  comparative  barbarities  of  Art. 
My  men  at  length  reached  the  first  station,  and  the 
measurement  commenced.  The  storm  drifted  up  the  val- 
ley, thickening  all  the  air  as  it  approached.  Denser  and 
denser  the  flakes  fell  ;*  but  still,  with  care  and  tact,  I  was 
able  to  follow  my  party  to  a  distance  of  800  yards.  I  had 
not  thought  it  possible  to  see  so  far  through  so  dense  a  storm. 
At  this  distance  also  my  voice  could  be  heard,  and  my 
instructions  understood  ;  for  once,  as  the  man  who  took 
up  the  line  stood  behind  his  baton  and  prevented  its  pro- 
jection against  the  white  snow,  I  called  out  to  him  to  stand 
aside,  and  he  promptly  did  so.  Throughout  the  entire 
measurement  the  snow  never  ceased  falling,  and  some  of 
the  illusions  which  it  produced  were  extremely  singular. 
The  distant  boundary  of  the  glacier  appeared  to  rise  to  an 
extraordinary  height,  and  the  men  wading  through  the  snow 
appeared  as  if  climbing  up  a  wall.  The  labour  along  this 
line  was  still  greater  than  on  the  former  ;  on  the  steeper 
slopes  especially  the  toil  was  great ;  for  here  the  effort  of 
the  leader  to  lift  his  own  body  added  itself  to  that  of  cut- 
ting his  way  through  the  snow.  His  footing  I  could  see 
often  yielded,  and  he  slid  back,  checking  his  recession, 
however,  by  still  plunging  forward ;  thus,  though  the 
limbs  were  incessantly  exerted,  it  was,  for  a  time,  a  mere 
motion  of  vibration  without  any  sensible  translation.  At 
the  last  stake  the  men  shouted,  "Nous  sommes finis!"  and 
I  distinctly  heard  them  through  the  falling  snow.  By  this 
time  I  was  quite  covered  with  the  crystals  which  clung  to 
my  wrapper.  They  also  formed  a  heap  upon  my  theodo- 
lite, rising  over  the  spirit-levels  and  embracing  the  lower 
portion  of  the  vertical  arc.  The  work  was  done ;  I  struck 


216  SWIFT  DESCENT.  [1859. 

my  theodolite  and  ascended  to  the  hotel ;  the  greatest 
depth  of  snow  through  which  I  waded  reaching,  when  I 
stood  erect,  to  within  three  inches  of  my  breast. 

The  men  returned ;  dinner  was  prepared  and  consumed ; 
the  disorder  which  we  had  created  made  good  ;  the  rooms 
were  swept,  the  mattresses  replaced,  and  the  shutters  fast- 
ened, where  this  was  possible.  We  locked  up'  the  house, 
and  with  light  hearts  and  lithe  limbs  commenced  the  de- 
scent. My  aim  now  was  to  reach  the  source  of  the  Arvei- 
ron,  to  examine  the  water  and  inspect  the  vault.  With  this 
view  we  went  straight  down  the  mountain.  The  inclina- 
tions were  often  extremely  steep,  and  down  these  we  swept 
with  an  avalanche-velocity  ;  indeed,  usually  accompanied 
by  an  avalanche  of  our  own  creation.  On  one  occasion 
Balmat  was  for  a  moment  overwhelmed  by  the  descending 
mass :  the  guides  were  startled,  but  he  emerged  instantly. 
Tairraz  followed  him,  and  I  followed  Tairraz,  all  of  us  roll- 
ing in  the  snow  at  the  bottom  of  the  slope  as  if  it  were  so 
much  flour.  My  practice  on  the  Finsteraarhorn  rendered 
me  at  home  here.  One  of  the  porters  could  by  no  means 
be  induced  to  try  this  flying  mode  of  descent.  Simond 
carried  my  theodolite  box,  tied  upon  a  crotchet  on  his 
back ;  and  once,  while  shooting  down  a  slope,  he  incau- 
tiously allowed  a  foot  to  get  entangled ;  his  momentum 
rolled  him  over  and  over  down  the  incline,  the  theodolite 
emerging  periodically  from  the  snow  during  his  successive 
revolutions.  A  succession  of  glissades  brought  us  with 
amazing  celerity  to  the  bottom  of  the  mountain,  whence 
we  picked  our  way  amid  the  covered  boulders  and  over  the 
concealed  arms  of  the  stream  to  the  source  of  the  Arveiron. 

The  quantity  of  water  issuing  from  the  vault  was  con- 
siderable, and  its  character  that  of  true  glacier  water.  It 
was  turbid  with  suspended  matter,  though  not  so  turbid  as 
in  summer ;  but  the  difference  in  force  and  quantity  would, 
I  think,  be  sufficient  to  account  for  the  greater  summer 


1859.]  VAULT  OF  THE  ARVEIRON.  217 

turbidity.  This  character  of  the  water  could  only  be  due 
to  the  grinding  motion  of  the  glacier  upon  its  bed,  —  a  mo- 
tion which  seems  not  to  be  suspended  even  in  the  depth^ 
of  winter.  The  temperature  of  the  water  was  the  tenth  of 
a  degree  Centigrade  above  zero ;  that  of  the  ice  was  half 
a  degree  below  zero :  this  was  also  the  temperature  of  the 
air,  while  that  of  the  snow,  which  in  some  places  covered 
the  ice-blocks,  was  a  degree  and  a  quarter  below  zero. 

The  entrance  to  the  vault  was  formed  by  an  arch  of  ice 
which  had  detached  itself  from  the  general  mass  of  the 
glacier  behind  :  between  them  was  a  space  through  which 
we  could  look  to  the  sky  above.  Beyond  this  the  cave 
narrowed,  and  we  found  ourselves  steeped  in  the  blue  light 
of  the  ice.  The  roof  of  the  inner  arch  was  perforated  at 
one  place  by  a  shaft  about  a  yard  wide,  which  ran  vertical- 
ly to  the  surface  of  the  glacier.  Water  had  run  down  the 
sides  of  this  shaft,  and,  being  re-frozen  below,  formed  a 
composite  pillar  of  icicles  at  least  twenty  feet  high  and  a 
yard  thick,  stretching  quite  from  roof  to  floor.  They  were 
all  united  to  a  common  surface  at  one  side,  but  at  the 
other  they  formed  a  series  of  flutings  of  exceeding  beauty. 
This  group  of  columns  was  bent  at  its  base  as  if  it  had 
yielded  to  the  forward  motion  of  the  glacier,  or  to  the 
weight  of  the  arch  overhead.  Passing  over  a  number  of 
large  ice-blocks  which  partially  filled  the  interior  of  the 
vault,  we  reached  its  extremity,  and  here  found  a  sloping 
passage  with  a  perfect  arch  of  crystal  overhead,  and  lead- 
ing by  a  steep  gradient  to  the  air  above.  This  singular 
gallery  was  about  seventy  feet  along,  and  was  floored  with 
snow.  We  crept  up  it,  and  from  the  summit  descended 
by  a  glissade  to  the  frontal  portion  of  the  cavern.  To  me 
this  crystal  cave,  with  the  blue  light  glistening  from  its 
walls,  presented  an  aspect  of  magical  beauty.  My  delight, 
however,  was  tame  compared  with  that  of  my  companions. 

Looking  from  the  blue  arch  westwards,  the  heavens 


218  MAJESTIC   SCENE.  [1859. 

were  seen  filled  by  crimson  clouds,  with  fiery  outlyers 
reaching  up  to  the  zenith.  On  quitting  the  vault  I  turned 
to  have  a  last  look  at  those  noble  sentinels  of  the  Mer  de 
Glace,  the  Aiguille  du  Dru,  and  the  Aiguille  Yerte.  The 
glacier  below  the  mountains  was  in  shadow,  and  its  frozen 
precipices  of  a  deep  cold  blue.  From  this,  as  from  a  basis, 
the  mountain  cones  sprang  steeply  heavenward,  meeting 
half-way  down  the  fiery  light  of  the  sinking  sun.  The 
right-hand  slopes  and  edges  of  both  pyramids  burned  in 
this  light,  while  detached  protuberant  masses  also  caught 
the  blaze,  and  mottled  the  mountains  with  effulgent 
spaces.  A  range  of  minor  peaks  ran  slanting  downwards 
from  the  summit  of  the  Aiguille  Verte  ;  some  of  these 
were  covered  with  snow,  and  shone  as  if  illuminated  with 
the  deep  crimson  of  a  strontian  flame.  I  was  absolutely 
struck  dumb  by  the  extraordinary  majesty  of  this  scene, 
and  watched  it  silently  till  the  red  light  faded  from  the 
highest  summits.  Thus  ended  my  winter  expedition  to 
the  Mer  de  Glace. 

Next  morning,  starting  at  three  o'clock,  I  was  driven 
by  my  two  guides  in  an  open  sledge  to  Sallenches.  The 
rain  was  pitiless  and  the  road  abominable.  The  distance, 
I  believe,  is  only  six  leagues,  but  it  took  us  five  hours  to 
accomplish  it.  The  leading  mule  was  beyond  the  reach 
of  Simond's  whip,  and  proved  a  mere  obstructive  ;  during 
part  of  the  way  it  was  unloosed,  tied  to  the  sledge,  and 
dragged  after  it.  Simond  afterwards  mounted  the  hind- 
most beast  and  brought  his  whip  to  bear  upon  the  leader  : 
the  jerking  he  endured  for  an  hour  and  a  half  seemed 
almost  sufficient  to  dislocate  his  bones.  We  reached  Sal- 
lenches half  an  hour  late,  but  the  diligence  was  behind 
its  time  by  this  exact  interval.  We  met  it  on  the  Pont  St. 
Martin,  and  I  transferred  myself  from  the  sledge  to  the 
interior.  This  was  the  morning  of  the  30th  of  December, 
and  on  the  evening  of  the  1st  of  January  I  was  in  London. 


1859.]  MY   ASSISTANTS.  219 

I  cannot  finish  this  recital  without  saying  one  word 
about  my  men.  Their  behaviour  was  admirable  through- 
out. The  labour  was  enormous,  but  it  was  manfully  and 
cheerfully  done.  I  know  Simond  well ;  he  is  intelligent, 
truthful,  and  affectionate,  and  there  is  no  guide  of  my  ac- 
quaintance for  whom  I  have  a  stronger  regard.  Joseph 
Tairraz  is  an  extremely  intelligent  and  able  guide,  and 
on  this  trying  occasion  proved  himself  worthy  of  my 
highest  praise  and  commendation.  Their  two  compan- 
ions upon  the  glacier,  Edouard  Balmat  (le  Petit  Balmat) 
and  Joseph  Simond  (fils  d'Auguste)  acquitted  ifchemselves 
admirably ;  and  it  also  gives  me  pleasure  to  bear  testi- 
mony to  the  willing  and  efficient  service  of  Francois 
Ravanal,  who  attended  upon  me  during  the  observa- 
tions. 


PART    II. 

CHIEFLY    SCIENTIFIC 


Aber  im  stillen  Gemach  entwirft  bedeutende  Zirkel 

Sinnend  der  Weise,  beschleicht  forschend  den  schaffenden  Geist, 

Priift  der  Stoffe  Gewalt,  der  Magnete  Hassen  und  Lieben, 

Folgt  durch  die  Lufte  dem  Klang,  folgt  durch  den  Aether  dem  Strahl, 

Sucht  das  vertraute  Gesetz  in  des  Zufall's  grausenden  Wundern, 
Sucht  den  ruhenden  Pol  in  der  Erscheinungen  Flucht. 

SCHILLER. 


ON   LIGHT  AND   HEAT. 


WHAT  is  Light  ?  The  ancients  supposed  it  to  be  some- 
thing emitted  by  the  eyes,  and  for  ages  no  notion  was 
entertained  that  it  required  time  to  pass  through  space. 
In  the  year  1676  Romer  first  proved  that  the  light  from 
Jupiter's  satellites  required  a  certain  time  to  cross  the 
earth's  orbit.  Bradley  afterwards  found  that,  owing  to 
the  velocity  with  which  the  earth  flies  through  space, 
the  rays  of  the  stars  are  slightly  inclined,  just  as  rain- 
drops which  descend  vertically  appear  to  meet  us  when 
we  move  swiftly  through  the  shower.  In  Kew  Gardens 
there  is  a  sun-dial  commemorative  of  this  discovery,  which 
is  called  the  aberration  of  light.  Knowing  the  velocity  of 
the  earth,  and  the  inclination  of  the  stellar  rays,  Bradley 
was  able  to  calculate  the  velocity  of  light  ;  and  his  result 
agrees  closely  with  that  of  Romer.  Celestial  distances 
were  here  involved,  but  a  few  years  ago  M.  Fizeau,  by 
an  extremely  ingenious  contrivance,  determined  the  time 
required  by  light  to  pass  over  a  distance  of  about  9,000 
yards  ;  and  his  experiment  is  quite  in  accordance  with  the 
results  of  his  predecessors. 

But  what  is  it  which  thus  moves  ?  Some,  and  among 
the  number  Newton,  imagined  light  to  consist  of  particles 
darted  out  from  luminous  bodies.  This  is  the  so-called 
Emission  Theory,  which  was  held  by  some  of  the  greatest 
men  :  Laplace,  for  example,  accepted  it  ;  and  M.  Biot 
has  developed  it  with  a  lucidity  and  power  peculiar  to 
himself.  It  was  first  opposed  by  the  astronomer  Huyghens, 
and  afterwards  by  Euler,  both  of  whom  supposed  light  to 


224  NATURE  OF  SOUND. 

be  a  kind  of  undulatory  motion ;  but  they  were  borne 
down  by  their  great  antagonists,  and  the  emission  theory 
held  its  ground  until  the  commencement  of  the  present 
century,  when  Thomas  Young,  Professor  of  Natural  Phi- 
losophy in  the  Royal  Institution,  reversed  the  scientific 
creed  by  placing  the  Theory  of  Undulation  on  firm  founda- 
tions. He  was  followed  by  a  young  Frenchman  of  extra- 
ordinary genius,  who,  by  the  force  of  his  logic  and  the 
collusiveness  of  his  experiments,  left  the  Wave  Theory 
without  a  competitor.  The  name  of  this  young  French- 
man was  Augustin  Fresnel. 

Since  his  time  some  of  the  ablest  minds  in  Europe  have 
been  applied  to  the  investigation  of  this  subject ;  and  thus 
a  mastery,  almost  miraculous,  has  been  attained  over  the 
grandest  and  most  subtle  of  natural  phenomena.  True 
knowledge  is  always  fruitful,  and  a  clear  conception  re- 
garding any  one  natural  agent  leads  infallibly  to  better 
notions  regarding  others.  Thus  it  is  that  our  knowledge 
of  light  has  corrected  and  expanded  our  knowledge  of 
heat,  while  the  latter,  in  its  turn,  will  assuredly  lead  us  to 
clearer  conceptions  regarding  the  other  forces  of  Nature. 

I  think  it  will  not  be  a  useless  labour  if  I  here  endeavour 
to  state,  in  a  simple  manner,  our  present  views  of  light 
and  heat.  Such  knowledge  is  essential  to  the  explanation 
of  many  of  the  phenomena  referred  to  in  the  foregoing 
pages  ;  and  even  to  the  full  comprehension  of  the  origin 
of  the  glaciers  themselves.  A  few  remarks  on  the  nature 
of  sound  will  form  a  fit  introduction. 

It  is  known  that  sound  is  conveyed  to  our  organs  of 
hearing  by  the  air :  a  bell  struck  in  a  vacuum  emits  no 
sound,  and  even  when  the  air  is  thin  the  sound  is  enfeebled. 
Hawksbee  proved  this  by  the  air-pump ;  De  Saussure  fired 
a  pistol  at  the  top  of  Mont  Blanc,  —  I  have  repeated  the 
experiment  myself,  and  found,  with  him,  that  the  sound  is 
feebler  than  at  the  sea  level.  Sound  is  not  produced  by 
anything  projected  through  the  air.  The  explosion  of  a 


CAUSE  OF  MUSIC.  225 

gun,  for  example,  is  sent  forward  by  a  motion  of  a  totally 
different  kind  from  that  which  animates  the  bullet  pro- 
jected from  the  gun  :  the  latter  is  a  motion  of  translation ; 
the  former,  one  of  vibration.  To  use  a  rough  comparison, 
sound  is  projected  through  the  air  as  a  push  is  through  a 
crowd  ;  it  is  the  propagation  of  a  wave  or  pulse,  each  par- 
ticle taking  up  the  motion  of  its  neighbour,  and  deliv- 
ering it  on  to  the  next.  These  aerial  waves  enter  the 
external  ear,  meet  a  membrane,  the  so-called  tympanic 
membrane,  which  is  drawn  across  the  passage  at  a  certain 
place,  and  break  upon  it  as  sea-waves  do  upon  the  shore. 
The  membrane  is  shaken,  its  tremors  are  communicated 
to  the  auditory  nerve,  and  transmitted  by  it  to  the  brain, 
where  they  produce  the  impression  to  which  we  give  the 
name  of  sound. 

In  the  tumult  of  a  city,  pulses  of  different  kinds  strike 
irregularly  upon  the  tympanum,  and  we  call  the  effect 
noise ;  but  when  a  succession  of  impulses  reach  the  ear 
at  regular  intervals ,  we  feel  the  effect  as  music.  Thus,  a 
vibrating  string  imparts  a  series  of  shocks  to  the  air  around 
it,  which  are  transmitted  with  perfect  regularity  to  the  ear, 
and  produce  a  musical  note.  When  we  hear  the  song  of 
a  soaring  lark,  we  may  be  sure  that  the  entire  atmosphere 
between  us  and  the  bird  is  filled  with  pulses,  or  undula- 
tions, or  waves,  as  they  are  often  called,  produced  by  the 
little  songster's  organ  of  voice.  This  organ  is  a  vibrating 
instrument,  resembling,  in  principle,  the  reed  of  a  clari- 
onet. Let  us  suppose  that  we  hear  the  song  of  a  lark, 
elevated  to  a  height  of  500  feet  in  the  air.  Before  this  is 
possible,  the  bird  must  have  agitated  a  sphere  of  air  1,000 
feet  in  diameter ;  that  is  to  say,  it  must  have  communi- 
cated to  17,888  tons  of  air  a  motion  sufficiently  intense  to 
be  appreciated  by  our  organs  of  hearing. 

Musical  sounds  differ  in  pitch  :  some  notes  are  high  and 
shrill,  others  low  and  deep.  Boys  are  chosen  as  choristers 
15 


226  CAUSE  OF  PITCH. 

to  produce  the  shrill  notes ;  men  are  chosen  to  produce 
the  bass  notes.  Now,  the  sole  difference  here  is,  that  the 
boy's  organ  vibrates  more  rapidly  than  the  man's,  —  it 
sends  a  greater  number  of  impulses  per  second  to  the  ear. 
In  like  manner,  a  short  string  emits  a  higher  note  than  a 
long  one,  because  it  vibrates  more  quickly.  The  greater 
the  number  of  vibrations  which  any  instrument  performs 
in  a  given  time,  the  higher  will  be  the  pitch  of  the  note 
produced.  The  reason  why  the  hum  of  a  gnat  is  shriller 
than  that  of  a  beetle  is  that  the  wings  of  the  small 
insect  vibrate  more  quickly  than  those  of  the  larger  one. 
We  can,  with  suitable  arrangements,  make  those  sonorous 
vibrations  visible  to  the  eye ;  *  and  we  also  possess  instru- 
ments which  enable  us  to  tell,  with  the  utmost  exactitude, 
the  number  of  vibrations  due  to  any  particular  note.  By 
such  instruments  we  learn  that  a  gnat  can  execute  many 
thousand  flaps  of  its  little  wings  in  a  second  of  time. 

In  the  study  of  nature,  the  coarser  phenomena,  which 
come  under  the  cognizance  of  the  senses,  often  suggest  to 
us  the  finer  phenomena  which  come  under  the  cognizance 
of  the  mind  ;  and  thus  the  vibrations  which  produce  sound, 
and  which,  as  has  been  stated,  can  be  rendered  visible  to 
the  eye  by  proper  means,  first  suggested  that  light  might 
be  due  to  a  somewhat  similar  action.  This  is  now  the 
universal  belief.  A  luminous  body  is  supposed  to  have  its 
atoms,  or  molecules,  in  a  state  of  intense  vibration.  The 

*  The  vibrations  of  the  air  of  a  room  in  which  a  musical  instrument  is 
sounded  may  be  made  manifest  by  the  way  in  which  fine  sand  arranges 
itself  upon  a  thin  stretched  membrane  over  which  it  is  strewn  ;  and  indeed 
Savart  has  thus  rendered  visible  the  vibrations  of  the  tympanum  itself. 
Every  trace  of  sand  was  swept  from  a  paper  drum  held  in  the  clock-tower  of 
Westminster  when  the  Great  Bell  was  sounded.  Another  way  of  showing 
the  propagation  of  aerial  pulses  is  to  insert  a  small  gas  jet  into  a  vertical 
glass  tube  about  a  foot  in  length,  in  which  the  flame  may  be  caused  to  burn 
tranquilly.  On  pitching  the  voice  to  the  note  of  an  open  tube  a  foot  long, 
the  little  flame  quivers,  stretches  itself,  and  responds  by  producing  a  clear 
melodious  note  of  the  same  pitch  as  that  which  excited  it.  The  flame  will 
continue  its  song  for  hours  without  intermission. 


NATURE  OF  LIGHT.  227 

motions  of  the  atoms  are  supposed  to  be  communicated  to 
a  medium  suited  to  their  transmission,  as  air  is  to  the 
transmission  of  sound.  This  medium  is  called  the  luml- 
niferous  ether,  and  the  little  billows  excited  in  it  speed 
through  it  with  amazing  celerity,  enter  the  pupil  of  the 
eye,  pass  through  the  humours,  and  break  upon  the  retina 
or  optic  nerve,  which  is  spread  out  at  the  back  of  the  eye. 
Hence  the  tremors  they  produce  are  transmitted  along  the 
nerve  to  the  brain,  where  they  announce  themselves  as 
light.  The  swiftness  with  which  the  waves  of  light  are 
propagated  through  the  ether,  is  however  enormously 
greater  than  that  with  which  the  waves  of  sound  pass 
through  the  air.  An  aerial  wave  of  sound  travels  at  about 
the  rate  of  1100  feet  in  a  second :  a  wave  of  light  leaves 
192,000  miles  behind  it  in  the  same  time. 

Thus,  then,  in  the  case  of  sound,  we  have  the  sonorous 
body,  the  air,  and  the  auricular  nerve,  concerned  in  the 
phenomenon ;  in  the  case  of  light,  we  have  the  luminous 
body,  the  ether,  and  the  optic  nerve.  The  fundamental 
analogy  of  sound  and  light  is  thus  before  us,  and  it  is 
easily  remembered.  But  we  must  push  the  analogy 
further.  We  know  that  the  white  light  which  comes  to 
us  from  the  sun  is  made  up  of  an  infinite  number  of 
coloured  rays.  By  refraction  with  a  prism  we  can  sepa- 
rate those  rays  from  each  other,  and  arrange  them  in  the 
series  of  colours  which  constitute  the  solar  spectrum. 
.The  rainbow  is  an  imperfect  or  impure  spectrum,  pro- 
duced by  the  drops  of  falling  rain ;  but  by  prisms  we  can 
unravel  the  white  light  into  pure  red,  orange,  yellow, 
green,  blue,  indigo,  and  violet.  Now,  this  spectrum  is  to 
the  eye  what  the  gamut  is  to  the  ear ;  each  colour  repre- 
sents a  note,  and  the  different  colours  represent  notes  of 
different  pitch.  The  vibrations  which  produce  the  im- 
pression of  red  are  slower,  and  the  waves  which  they  pro- 
duce are  longer,  than  those  to  which  we  owe  tho  sensa- 


228  CAUSE  OF   COLOUR. 

tion  of  violet ;  while  the  vibrations  which  excite  the  other 
colours  are  intermediate  between  these  two  extremes. 
This,  then,  is  the  second  grand  analogy  between  light  and 
sound :  Colour  answers  to  Pitch.  There  is  therefore 
truth  in  the  figure  when  we  say  that  the  gentian  of  the 
Alps  sings  a  shriller  note  than  the  wild  rhododendron, 
and  that  the  red  glow  of  the  mountains  at  sunset  is  of  a 
lower  pitch  than  the  blue  of  the  firmament  at  noon. 

These  are  not  fanciful  analogies.  To  the  mind  of  the 
philosopher  these  waves  of  ether  are  almost  as  palpable 
and  certain  as  the  waves  of  the  sea,  or  the  ripples  on  the 
surface  of  a  lake.  The  length  of  the  waves,  both  of  sound 
and  light,  and  the  number  of  shocks  which  they  respec- 
tively impart  to  the  ear  and  eye,  have  been  the  subjects  of 
the  strictest  measurement.  Let  us  here  go  through  a 
simple  calculation.  It  has  been  found  that  39,000,  waves 
of  red  light  placed  end  to  end  would  make  up  an  inch. 
How  many  inches  are  there  in  192,000  miles  ?  My 
youngest  reader  can  make  the  calculation  for  himself, 
and  find  the  answer  to  be  12,165,120,000  inches.  It  is 
evident  that,  if  we  multiply  this  number  by  39,000,  we 
shall  obtain  the  number  of  waves  of  red.  light  in  192,000 
miles;  this  number  is  474,439,680,000,000.  All  these 
waves  enter  the  eye  in  one  second;  thus  the  expression 
"  I  see  red  colour,"  strictly  means,  "  My  eye  is  now  in 
receipt  of  four  hundred  and  seventy-four  millions  of 
millions  of  impulses  per  second."  To  produce  the  im- 
pression of  violet  light  a  still  greater  number  of  impulses 
is  necessary ;  the  wave-length  of  violet  is  the  -srius-th 
part  of  an  inch,  and  the  number  of  shocks  imparted  in 
a  second  by  waves  of  this  length  is,  in  round  numbers,  six 
hundred  and  ninety-nine  millions  of  millions.  The  other 
colours  of  the  spectrum,  as  already  stated,  rise  gradually 
in  pitch  from  the  red  to  the  violet. 

A  very  curious  analogy  between  the  eye  and  ear  may 


LENGTH  OF  ETHEREAL  WAVES.  229 

here  be  noticed.  The  range  of  seeing  is  different  in  dif- 
ferent persons,  —  some  see  a  longer  spectrum  than  others ; 
that  is  to  say,  rays  which  are  obscure  to  some  are  luminous 
to  others.  Dr.  Wollaston  pointed  out  a  similar  fact  as  re- 
gards' hearing  ;  the  range  of  which  differs  in  different  in- 
dividuals. Savart  has  shown  that  a  good  ear  can  hear  a 
musical  note  produced  by  8  shocks  in  a  second  ;  it  can 
also  hear  a  note  produced  by  24,000  shocks  in  a  second  ; 
but  there  are  ears  in  which  the  range  is  much  more 
limited.  It  is  possible  indeed  to  produce  a  sound  which 
shall  be  painfully  shrill  to  one  person,  while  it  is  quite 
unheard  by  another.  I  once  crossed  a  Swiss  mountain  in 
company  with  a  friend :  a  donkey  was  in  advance  of  us, 
and  the  dull  tramp  of  the  animal  was  plainly  heard  by  my 
companion ;  but  to  me  this  sound  was  almost  masked  by 
the  shrill  chirruping  of  innumerable  insects  which  thronged 
the  adjacent  grass ;  my  friend  heard  nothing  of  this,  it  lay 
quite  beyond  his  range  of  hearing. 

A  third  and  most  important  analogy  between  sound  and 
light  is  now  to  be  noted ;  and  it  will  be  best  understood 
by  reference  to  something  more  tangible  than  either. 
When  a  stone  is  thrown  into  calm  water  a  series  of  rings 
spread  themselves  around  the  centre  of  disturbance.  If  a 
second  stone  be  thrown  in  at  some  distance  from  the  first, 
the  rings  emanating  from  both  centres  will  cross  each  other, 
and  at  those  points  where  the  ridge  of  one  wave  coincides 
with  the  ridge  of  another  the  water  will  be  lifted  to  a 
greater  height.  At  those  points,  on  the  contrary,  where 
the  ridge  of  one  wave  crosses  the  furrow  of  another,  we 
have  both  obliterated,  and  the  water  restored  to  its  ordinary 
level.  Where  two  ridges  or  two  furrows  unite,  we  have  a 
case  of  coincidence ;  but  where  a  ridge  and  a  furrow  unite, 
we  have  what  is  called  interference.  It  is  quite  possible  to 
send  two  systems  of  waves  into  the  same  channel,  and  to 
hold  back  one  system  a  little,  so  that  its  ridges  shall  coin- 


230      LIGHT  ADDED  TO  LIGHT  MAKES  DARKNESS. 

cide  with  the  furrows  of  the  other  system.  The  "  inter- 
ference "  would  be  here  complete,  and  the  waves  thus 
circumstanced  would  mutually  destroy  each  other,  smooth 
water  being  the  result.  In  this  way,  by  the  addition  of 
motion  to  motion,  rest  may  be  produced. 

In  a  precisely  similar  manner  two  systems  of  sonorous 
waves  can  be  caused  to  interfere  and  mutually  to  destroy 
each  other :  thus,  by  adding  sound  to  sound,  silence  may 
be  produced.  Two  beams  of  light  also  may  be  caused  to 
interfere  and  effect  their  mutual  extinction :  thus,  by 
adding  light  to  light,  we  can  produce  darkness.  Here 
indeed  we  have  a  critical  analogy  between  sound  and 
light,  —  the  one,  in  fact,  which  compels  the  most  profound 
thinkers  of  the  present  day  to  assume  that  light,  like  sound, 
is  a  case, of  undulatory  motion. 

We  see  here  the  vision  of  the  intellect  prolonged 
beyond  the  boundaries  of  sense  into  the  region  of  what 
might  be  considered  mere  imagination.  But,  unlike  other 
imaginations,  we  can  bring  ours  to  the  test  of  experiment ; 
indeed,  so  great  a  mastery  have  we  obtained  over  these 
waves,  which  eye  has  not  seen,  nor  ear  heard,  that  we 
can  with  mathematical  certainty  cause  them  to  coin- 
cide or  to  interfere,  to  help  each  other  or  to  destroy 
each  other,  at  pleasure.  It  is  perhaps  possible  to  be  a 
little  more  precise  here.  Let  two  stones  —  with  a  small 
distance  between  them  —  be  dropped  into  water  at  the 
same  moment ;  a  system  of  circular  waves  will  be  formed 
round  each  stone.  Let  the  distance  from  one  little  crest 
to  the  next  following  one  be  called  the  length  of  the 
wave,  and  now  let  us  inquire  what  will  take  place  at 
a  point  equally  distant  from  the  places  where  the  two 
stones  were  dropped  in.  Fixing  our  attention  upon  the 
ridge  of  the  first  wave  in  each  case,  it  is  manifest  that, 
as  the  water  propagates  both  systems  with  the  same  velo- 
city, the  two  foremost  ridges  will  reach  the  point  in 


COINCIDENCE  AND   INTERFERENCE.  231 

question  at  the  same  moment ;  the  ridge  of  one  would 
therefore  coincide  with  the  ridge  of  the  other,  and  the 
water  at  this  point  would  be  lifted  to  a  height  greater 
than  that  of  either  of  the  previous  ridges. 

Again,  supposing  that  by  any  means  we  had  it  in  our 
power  to  retard  one  system  of  waves  so  as  to  cause  the 
first  ridge  of  the  one  to  be  exactly  one  wave  length  behind 
the  first  ridge  of  the  other,  when  they  arrive  at  the  point 
referred  to.  It  is  plain  that  the  first  ridge  of  the  re- 
tarded system  now  falls  in  with  the  second  ridge  of  the 
unretarded  system,  and  we  have  another  case  of  coinci- 
dence. A  little  reflection  will  shew  the  same  to  be  true 
when  one  system  is  retarded  any  number  of  whole  wave- 
lengths ;  the  first  ridge  of  the  retarded  system  will  always, 
at  the  point  referred  to,  coincide  with  a  ridge  of  the  un- 
retarded system. 

But  now  suppose  the  one  system  to  be  retarded  only 
half  a  wave-length  ;  it  is  perfectly  clear  that  in  this  case 
the  first  ridge  of  the  retarded  system  would  fall  in  with 
the  first  furrow  of  the  unretarded  system,  and  instead  of 
coincidence  we  should  have  interference.  One  system,  in 
fact,  would  tend  to  make  a  hollow  at  the  point  referred  to, 
the  other  would  tend  to  make  a  hill,  and  thus  both  systems 
would  oppose  and  neutralise  each  other,  so  that  neither 
the  hollow  nor  the  hill  would  be  produced  ;  the  water 
would  maintain  its  ordinary  level.  What  is  here  said  of 
a  single  half-wave-length  of  retardation,  is  also  true  if 
the  retardation  amount  to  any  odd  number  of  half-wave- 
lengths. In  all  such  cases  we  should  have  the  ridge  of 
the  one  system  falling  in  with  the  furrow  of  the  other  ;  a 
mutual  destruction  of  the  waves  of  both  systems  being  the 
consequence.  The  same  remarks  apply  when  the  point, 
instead  of  being  equally  distant  from  both  stones,  is  an 
even  or  an  odd  number  of  semi-undulations  farther  from 
the  one  than  from  the  other.  In  the  former  case  we 


232  LIQUID   WAVES. 

should  have  coincidence,  and  in  the  latter  case  interfer- 
ence, at  the  point  in  question. 

To  the  eye  of  a  person  who  understands  these  things, 
nothing  can  be  more  interesting  than  the  rippling  of  water 
under  certain  circumstances.  By  the  action  of  interfer- 
ence its  surface  is  sometimes  shivered  into  the  most  beau- 
tiful mosaic,  shifting  and  trembling  as  if  with  a  kind  of 
visible  music.  When  the  tide  advances  over  a  sea-beach 
on  a  calm  and  sunny  day,  and  its  tiny  ripples  enter,  at 
various  points,  the  clear  shallow  pools  which  the  preced- 
ing tide  had  left  behind,  the  little  wavelets  run  and  climb 
and  cross  each  other,  and  thus  form  a  lovely  chasing-, 
which  has  its  counterpart  in  the  lines  of  light  converged 
by  the  ripples  upon  the  sand  underneath.  When  waves 
are  skilfully  generated  in  a  vessel  of  mercury,  and  a  strong 
light  reflected  from  the  surface  of  the  metal  is  received 
upon  a  screen,  the  most  beautiful  effects  may  be  observed. 
The  shape  of  the  vessel  determines,  in  part,  the  character 
of  the  figures  produced ;  in  a  circular  dish  of  mercury, 
for  example,  a  disturbance  at  the  centre  propagates  itself 
in  circular  waves,  which  after  reflection  again  encircle  the 
centre.  If  the  point  of  disturbance  be  a  little  removed 
from  the  centre,  the  intersections  of  the  direct  and  re- 
flected waves  produce  the  magnificent  chasing  shown  in 
the  annexed  figure  (16),  which  I  have  borrowed  from  the 
excellent  work  on  Waves  by  the  Messrs.  Weber.  The 
luminous  figure  reflected  from  such  a  surface  is  exceed- 
ingly beautiful.  When  the  mercury  is  lightly  struck  by 
a  glass  point,  in  a  direction  concentric  with  the  circum- 
ference of  the  vessel,  the  lines  of  light  run  round  the 
vessel  in  mazy  coils,  interlacing  and  unravelling  them- 
selves in  the  most  wonderful  manner.  If  the  vessel  be 
square,  a  splendid  mosaic  is  produced  by  the  crossing  of 
the  direct  and  reflected  waves.  Description,  however, 
can  give  but  a  feeble  idea  of  these  exquisite  effects ;  — 


CHASING  PRODUCED  BY  WAVES.  233 

"  Thou  canst  not  wave  thy  staff  in  the  air, 

Or  dip  thy  paddle  in  the  lake, 
But  it  carves  the  brow  of  beauty  there, 
And  the  ripples  in  rhymes  the  oar  forsake." 

Now,  all  that  we  have  said  regarding  the  retardation  of 
the  waves  of  water,  by  a  whole  undulation  and  a  semi- 


Fig.  16. 

undulation,  is  perfectly  applicable  to  the  case  of  light. 
Two  luminous  points  may  be  placed  near  to  each  other,  so 
as  to  resemble  the  two  stones  dropped  into  the  water ;  and 
when  the  light  of  these  is  properly  received  upon  a  screen, 
or  directly  upon  the  retina,  we  find  that  at  some  places  the 
action  of  the  rays  upon  each  other  produces  darkness,  and  at 
others  augmented  light.  The  former  places  are  those  where 
the  rays  emitted  from  one  point  are  an  odd  number  of  semi- 
undulations  in  advance  of  the  rays  sent  from  the  other ; 
the  latter  places  are  those  where  the  difference  of  path 
described  by  the  rays  is  either  nothing,  or  an  even  number  of 


234 


EFFECT  OF  RETAEDATION. 


semi-undulations.  Supposing  a  and  b  (Fig.  17)  to  be  two 
such  sources  of  light,  and  s  R  a  screen  on  which  the  light 
falls ;  at  a  point  /,  equally  distant  from  a  and  £,  we  have 
light ;  at  a  point  d,  where  a  d  is  half  an  undulation  longer 
than  b  d,  we  have  darkness ;  at  /',  where  a  I'  is  a  whole 
wave-length,  or  two  semi-undulations,  longer  than  b  I',  we 


R 


again  have  light ;  and  at  a  point  d'*  where  the  difference 
is  three  semi-undulations,  we  have  darkness  ;  and  thus  we 
obtain  a  series  of  bright  and  dark  spaces  as  we  recede  lat- 
erally from  the  central  point  /. 

Let  a  bit  of  tinfoil  be  closely  pasted  upon  a  piece  of  glass, 
and  the  edge  of  a  penknife  drawn  across  the  foil  so  as  to 
produce  a  slit.  Looking  through  this  slit  at  a  small  and 
distant  light,  we  find  the  light  spread  out  in  a  direction  at 
right  angles  to  the  slit,  and  if  the  light  looked  at  be  mono- 
chromatic, that  is,  composed  of  ,a  single  colour,  we  shall 
have  a  series  of  bright  and  dark  bars  corresponding  to  the 
points  at  which  the  rays  from  the  different  points  of  the 
slit  alternately  coincide  and  interfere  upon  the  retina. 

*  The  accent '  is  omitted  in  the  figure ;  the  second  d  counting  from  I  is 
meant. 


CHROMATIC  EFFECTS.  285 

By  properly  drawing  a  knife  across  a  sheet  of  letter-paper 
a  suitable  slit  may  also  be  obtained  ;  and  those  practised 
in  such  things  can  obtain  the  effect  by  looking  through 
their  fingers  or  their  eyelashes. 

But  if  the  light  looked  at  be  white,  the  light  of  a  candle 
for  example,  or  a  jet  of  gas,  instead  of  having  a  series  of 
bright  and  dark  bars,  we  have  the  bars  coloured.  And 
see  how  beautifully  this  harmonizes  with  what  has  been 
already  said  regarding  the  different  lengths  of  the  waves 
which  produce  different  colours.  Looking  again  at  Fig.  17 
we  see  that  a  certain  obliquity  is  necessary  to  cause  one 
ray  to  be  a  whole  undulation  in  advance  of  the  other  at 
the  point  I1 ;  but  it  is  perfectly  manifest  that  the  obliquity 
must  depend  upon  the  length  of  the  undulation  ;  a  long 
undulation  would  require  a  greater  obliquity  than  a  short 
one  ;  red  light,  for  example,  requires  a  greater  obliquity 
than  blue  light ;  so  that  if  the  point  I'  represents  the  place 
where  the  first  bar  of  red  light  would  be  at  its  maximum 
strength,  the  maximum  for  blue  would  lie  a  little  to  the 
left  of  /' ;  the  different  colours  are  in  this  way  separated 
from  each  other,  and  exhibit  themselves  as  distinct  fringes 
when  a  distant  source  of  white  light  is  regarded  through 
a  narrow  slit. 

By  varying  the  shape  of  the  apertiire  we  alter  the  form 
of  the  chromatic  image.  A  circular  aperture,  for  exam- 
ple, placed  in  front  of  a  telescope  through  which  a  point 
of  white  light  is  regarded,  is  seen  surrounded  by  a  con- 
centric system  of  coloured  rings.  If  we  multiply  our 
slits  or  apertures  the  phenomena  augment  in  complexity 
and  splendour.  To  give  some  notion  of  this,  observe  in 
the  excellent  work  of  M.  Schwerd  the  figure  which  repre- 
sents the  gorgeous  effect  shown  when  a  distant  point  of 
light  is  looked  at  through  two  gratings  with  slits  of  differ- 
ent widths.*  A  bird's  feather  represents  a  peculiar  sys- 

*  I  am  not  aware  whether  in  his  own  country,  or  in  any  other,  a  recogni- 
tion at  all  commensurate  with  the  value  of  the  performance  has  followed 


COLOURS  OF  THIN  FILMS. 

tern  of  slits,  and  the  effect  observed  on  properly  looking 
through  it  is  extremely  interesting. 

There  are  many  ways  by  which  the  retardation  neces- 
sary to  the  production  of  interference  is  effected.  The 
splendid  colours  of  a  soap-bubble  are  entirely  due  to  in- 
terference ;  the  beam  falling  upon  the  transparent  film  is 
partially  reflected  at  its  outer  surface,  but  a  portion  of  it 
enters  the  film  and  is  reflected  at  its  inner  surface.  The 
latter  portion,  having  crossed  the  film  and  returned,  is  re- 
tarded, in  comparison  with  the  former,  and,  if  the  film  be 
of  suitable  thickness,  these  two  beams  will  clash  and  ex- 
tinguish each  other,  while  another  thickness  will  cause  the 
beams  to  coincide  and  illuminate  the  film  with  a  light  of 
greater  intensity.  From  what  has  been  said  it  must  be 
manifest  that,  to  make  two  red  beams  thus  coincide,  a 
thicker  film  would  be  required  than  would  be  necessary 
for  two  blue  or  green  beams ;  thus,  when  the  thickness 
of  the  bubble  is  suitable  for  the  development  of  red,  it  is 
not  suitable  for  the  development  of  green,  blue,  &c. ;  the 
consequence  is  that  we  have  different  colours  at  different 
parts  of  the  bubble.  Owing  to  its  compactness  and  to 
its  being  shaded  by  a  covering  of  debris  from  the  direct 
heat  of  the  sun,  the  ice  underneath  the  moraines  of  gla- 
ciers appears  sometimes  of  a  pitchy  blackness.  While 
cutting  such  ice  with  my  axe  I  have  often  been  surprised 
and  delighted  by  sudden  flashes  of  coloured  light  which 
broke  like  fire  from  the  mass.  These  flashes  were  due  to 
internal  rupture,  by  which  fissures  were  produced  as  thin 
as  the  film  of  a  soap-bubble  ;  the  colours  being  due  to  the 
interference  of  the  light  reflected  from  the  opposite  sides 
of  the  fissures. 

If  spirit  of  turpentine,  or  olive  oil,  be  thrown  upon 
water,  it  speedily  spreads  in  a  thin  film  over  the  surface, 

Schwerd's  admirable  essay  entitled  "The  Phenomena  of  Diffraction  deduced 
from  the  Theory  of  Undulation." 


DIFFRACTION.  237 

and  the  most  gorgeous  chromatic  phenomena  may  be  thus 
produced.  Oil  of  lemons  is  also  peculiarly  suited  to  this 
experiment.  If  water  be  placed  in  a  tea-tray,  and  light 
of  sufficient  intensity  be  suffered  to  fall  upon  it,  this  light 
will  be  reflected  from  the  upper  and  under  surfaces  of 
the  film  of  oil,  and  the  colours  thus  produced  may  be  re- 
ceived upon  a  screen,  and  seen  at  once  by  many  hundred 
persons.  If  the  oil  of  cinnamon  be  used,  fine  colours  are 
also  obtained,  and  the  breaking  up  of  this  film  exhibits  a 
most  interesting  case  of  molecular  action.  By  using  a 
kind  of  varnish  instead  of  oil,  Mr.  Delarue  has  imparted 
such  tenacity  to  these  films  that  they  may  be  removed 
from  the  water  on  which  they  rest  and  preserved  for  any 
length  of  time.  By  such  films  the  colours  of  certain 
beetles,  and  of  the  wings  of  certain  insects,  may  be  accu- 
rately imitated  ;  and  a  rook's  feather  may  be  made  to 
shine  with  magnificent  iridescences.  The  colours  of  tem- 
pered metals,  and  the  beautiful  metallochrome  of  Nobili 
are  also  due  to  a  similar  cause. 

These  colours  are  called  the  colours  of  thin  plates,  and 
are  distinguished  in  treatises  on  optics  from  the  coloured 
bars  and  fringes  above  referred  to,  and  which  are  pro- 
duced by  diffraction,  or  the  bending  of  the  waves  round 
the  edge  of  an  object.  One  result  of  this  bending,  which 
is  of  interest  to  us,  was  obtained  by  the  celebrated  Thomas 
Young.  Permitting  a  beam  of  sunlight  to  enter  a  dark 
room  through  an  aperture  made  with  a  fine  needle,  and 
placing  in  the  path  of  the  beam  a  bit  of  card  one-thirtieth 
of  an  inch  wide,  he  found  the  shadow  of  this  card,  or 
rather  the  line  on  which  its  shadow  might  be  supposed  to 
fall,  always  bright;  and  he  proved  the  effect  to  be  due 
to  the  bending  of  the  waves  of  ether  round  the  two  edges 
of  the  card,  and  their  coincidence  at  the  other  side.  It 
has,  indeed,  been  shown  by  M.  Poisson,  that  the  centre 
of  the  shadow  of  a  small  circular  opaque  disk  which 


238          CLOUD  IRIDESCENCES,  ETC.  EXPLAINED. 

stands  in  the  way  of  a  beam  diverging  from  a  point  is 
exactly  as  much  illuminated  as  if  the  disk  were  absent. 
The  singular  effects  described  by  M.  Necker  in  the  letter 
quoted  at  page  178  at  once  suggest  themselves  here  ;  and 
we  see  how  possible  it  is  for  the  solar  rays,  in  grazing  a 
distant  tree,  so  to  bend  round  it  as  to  produce  upon  the 
retina,  where  shadow  might  be  expected,  the  impression 
of  a  tree  of  light.*  Another  effect  of  diffraction  is  espe- 
cially interesting  to  us  at  present.  Let  the  seed  of  lyco- 
podium  be  scattered  over  a  glass  plate,  or  even  like  a 
cloud  in  the  air,  and  let  a  distant  point  of  light  be 
regarded  through  it ;  the  luminous  point  will  appear  sur- 
rounded by  a  series  of  coloured  rings,  and  when  the  light 
is  intense,  like  the  electric  or  the  Drummond  light,  the 
effect  is  exceedingly  fine. 

And  now  for  the  application  of  these  experiments.  I 
have  already  mentioned  a  series  of  coloured  rings  observed 
around  the  sun  by  Mr.  Huxley  and  myself  from  the  Rhone 
glacier  ;  I  have  also  referred  to  the  cloud  iridescences  on 
the  Aletschhorn  ;  and  to  the  colours  observed  during  my 
second  ascent  of  Monte  Rosa,  the  magnificence  of  which 
is  neither  to  be  rendered  by  pigments  nor  described  in 
words.  All  these  splendid  phenomena  are,  I  believe,  pro- 
duced by  diffraction,  the  vesicles  or  spherules  of  water  in 
the  case  of  the  cloud  acting  the  part  of  the  sporules  in  the 
case  of  the  lycopodium.  The  coloured  fringe  which  sur- 
rounds the  Spirit  of  the  Brocken,  and  the  spectra  which  I 
have  spoken  of  as  surrounding  the  sun,  are  also  produced  by 
diffraction.  By  the  interference  of  their  rays  in  the  earth's 
atmosphere  the  stars  can  momentarily  quench  themselves ; 
and  probably  to  an  intermittent  action  of  this  kind  their 
twinkling,  and  the  swift  chromatic  changes  already  men- 
tioned, are  due.  Does  not  all  this  sound  more  like  a  fairy 

*  I  think,  however,  that  the  strong  irradiation  from  the  glistening  sides  of 
the  twigs  and  branches  must  also  contribute  to  the  result. 


RADIANT  HEAT.  239 

tale  than  the  sober  conclusions  of  science  ?  What  effort  of 
the  imagination  could  transcend  the  realities  here  pre- 
sented to  us  ?  The  ancients  had  their  spheral  melodies, 
but  have  not  we  ours,  which  only  want  a  sense  sufficiently 
refined  to  hear  them  ?  Immensity  is  filled  with  this  mu- 
sic ;  wherever  a  star  sheds  its  light,  its  notes  are  heard. 
Our  sun,  for  example,  thrills  concentric  waves  through 
space,  and  every  luminous  point  that  gems  our  skies  is 
surrounded  by  a  similar  system.  I  have  spoken  of  the 
rising,  climbing,  and  crossing  of  the  tiny  ripples  of  a  calm 
tide  upon  a  smooth  strand ;  but  what  are  they  to  those 
intersecting  ripples  of  the  "  uncontinented  deep"  by  which 
Infinity  is  engine-turned  !  Crossing  solar  and  stellar  dis- 
tances, they  bring  us  the  light  of  sun  and  stars  ;  thrilled 
back  from  our  atmosphere,  they  give  us  the  blue  radiance 
of  the  sky ;  rounding  liquid  spherules,  they  clash  at  the 
other  side,  and  the  survivors  of  the  tumult  bear  to  our 
vision  the  wondrous  cloud-dyes  of  Monte  Rosa. 


(2.) 

THUS,  then,  we  have  been  led  from  Sound  to  Light,  and 
light  now  in  its  turn  will  lead  us  to  Radiant  Heat ;  for 
in  the  order  in  which  they  are  here  mentioned  the 
conviction  arose  that  they  are  all  three  different  kinds  of 
motion.  It  has  been  said  that  the  beams  of  the  sun  con- 
sist of  rays  of  different  colours,  but  this  is  not  a  complete 
statement  of  the  case.  The  sun  emits  a  multitude  of  rays 
which  are  perfectly  non-luminous ;  and  the  same  is  true,  in  a 
still  greater  degree,  of  our  artificial  sources  of  illumination. 
Measured  by  the  quantity  of  heat  which  they  produce,  90 
per  cent,  of  the  rays  emanating  from  a  flame  of  oil  are 


240  OBSCURE  KAYS. 

obscure  ;  while  99  out  of  every  100  of  those  which  ema- 
nate from  an  alcohol  flame  are  of  the  same  description.* 

In  fact,  the  visible  solar  spectrum  simply  embraces  an 
interval  of  rays  of  which  the  eye  is  formed  to  take  cog- 
nizance, but  it  by  no  means  marks  the  limits  of  solar 
action.  Beyond  the  violet  end  of  the  spectrum  we  have 
obscure  rays  capable  of  producing  chemical  changes,  and 
beyond  the  red  we  have  rays  possessing  a  high  heating- 
power,  but  incapable  of  exciting  the  impression  of  light. 
This  latter  fact  was  first  established  by  Sir  William  Her- 
schel,  and  it  has  been  amply  corroborated  since. 

The  belief  now  universally  prevalent  is,  that  the  rays  of 
heat  differ  from  the  rays  of  light  simply  as  one  colour  dif- 
fers from  another.  As  the  waves  which  produce  red  are 
longer  than  those  which  produce  yellow,  so  the  waves 
which  produce  this  obscure  heat  are  longer  than  those 
which  produce  red.  In  fact,  it  may  be  shown  that  the 
longest  waves  never  reach  the  retina  at  all ;  they  are  com- 
pletely absorbed  by  the  humours  of  the  eye. 

What  is  true  of  the  sun's  obscure  rays  is  also  true  of 
calorific  rays  emanating  from  any  obscure  source,  —  from 
our  own  bodies,  for  example,  or  from  the  surface  of  a 
vessel  containing  boiling  water.  We  must,  in  fact,  figure 
a  warm  body  also  as  having  its  particles  in  a  state  of  vibra- 
tion. When  these  motions  are  communicated  from  particle 
to  particle  of  the  body,  the  heat  is  said  to  be  conducted ; 
when,  on  the  contrary,  the  particles  transmit  their  vibra- 
tions through  the  surrounding  ether,  the  heat  is  said  to 
be  radiant.  This  radiant  heat,  though  obscure,  exhibits  a 
deportment  exactly  similar  to  light.  It  may  be  refracted 
and  reflected,  and  collected  in  the  focus  of  a  mirror  or  of  a 
suitable  lens.  The  principle  of  interference  also  applies 
to  it,  so  that  by  adding  heat  to  heat  we  can  produce  cold. 
The  identity  indeed  is  complete  throughout,  and,  recurring 

*  Melloni. 


HEAT  A  KIND  OF  MOTION.  241 

to  the  analogy  of  sound,  we  might  define  this  radiant  heat 
to  be  light  of  too  low  a  pitch  to  be  visible. 

I  have  thus  far  spoken  of  obscure  heat  only ;  but  the 
selfsame  ray  may  excite  both  light  and  heat.  The  red  rays 
of  the  spectrum  possess  a  very  high  heating  power.  It  was 
once  supposed  that  the  heat  of  the  spectrum  was  an 
essence  totally  distinct  from  its  light ;  but  a  profounder 
knowledge  dispels  this  supposition,  and  leads  us  to  infer 
that  the  selfsame  ray,  falling  upon  the  nerves  of  feeling, 
excites  heat,  and  falling  upon  the  nerves  of  seeing,  excites 
light.  As  the  same  electric  current,  if  sent  round  a  mag- 
netic needle,  along  a  wire,  and  across  a  conducting  liquid, 
produces  different  physical  eifects,  so  also  the  same  agent 
acting  upon  different  organs  of  the  body  affects  our  con- 
sciousness differently. 


(3.) 

HEAT  has  been  defined  in  the  foregoing  section  as  a 
motion  of  the  molecules  or  atoms  of  a  body  ;  but  though 
the  evidence  in  favour  of  this  view  is  at  present  over- 
whelming, I  do  not  ask  the  reader  to  accept  it  as  a  cer- 
tainty, if  he  feels  sceptically  disposed.  In  this  case,  I 
would  only  ask  him  to  accept  it  as  a  symbol.  Regarded 
as  a  mere  physical  image,  a  kind  of  paper-currency  of  the 
mind,  convertible,  in  due  time,  into  the  gold  of  truth,  the 
hypothesis  will  be  found  exceedingly  useful. 

All  known  bodies  possess  more  or  less  of  this  molecular 
motion,  and  all  bodies  are  communicating  it  to  the  ether 
in  which  they  are  immersed.  Ice  possesses  it.  Ice  before 
it  melts  attains  a  temperature  of  32°  Fahr.,  but  the  sub- 
stance in  winter  often  possesses  a  temperature  far  below 
32°,  so  that  in  rising  to  32°  it  is  warmed.  In  experiment- 
16 


242  QUALITIES   OF  HEAT. 

ing  with  ice  I  have  often  had  occasion  to  cool  it  to  100° 
and  more  below  the  freezing  point,  and  to  warm  it  after- 
wards up  to  32°. 

If  then  we  stand  before  a  wall  of  ice,  the  wall  radiates 
heat  to  us,  and  we  also  radiate  heat  to  it ;  but  the  quan- 
tity which  we  radiate  being  greater  than  that  which  the 
ice  radiates,  we  lose  more  than  we  gain,  and  are  conse- 
quently chilled.  If,  on  the  contrary,  we  stand  before  a 
warm  stove,  a  system  of  exchanges  also  takes  place ;  but 
here  the  quantity  we  receive  is  in  excess  of  the  quantity 
lost,  and  we  are  warmed  by  the  difference. 

In  like  manner  the  earth  radiates  heat  by  day  and  by 
night  into  space,  and  against  the  sun,  moon,  and  stars. 
By  day,  however,  the  quantity  received  is  greater  than 
the  quantity  lost,  and  the  earth  is  warmed  ;  by  night  the 
conditions  are  reversed ;  the  earth  radiates  more  heat 
than  is  sent  to  her  by  the  moon  and  stars,  and  she  is  con- 
sequently cooled. 

But  here  an  important  point  is  to  be  noted:  —  the  earth 
receives  the  heat  of  the  sun,  moon,  and  stars,  in  great  part 
as  luminous  heat,  but  she  gives  it  out  as  obscure  heat.  I 
do  not  now  speak  of  the  heat  reflected  by  the  earth  into 
space,  as  the  light  of  the  moon  is  to  us  ;  but  of  the  heat 
which,  after  it  has  been  absorbed  by  the  earth,  and  has 
contributed  to  warm  it,  is  radiated  into  space,  as  if  the  earth 
itself  were  its  independent  source.  Thus  we  may  properly 
say  that  the  heat  radiated  from  the  earth  is  different  in 
quality  from  that  which  she  has  received  from  the  sun. 

In  one  particular  especially  does  this  difference  of  qual- 
ity show  itself;  besides  being  non-luminous,  the  heat 
radiated  from  the  earth  is  more  easily  intercepted  and 
absorbed  by  almost  all  transparent  substances.  A  vast 
portion  of  the  sun's  rays,  for  example,  can  pass  instan- 
taneously through  a  thick  sheet  of  water ;  gunpowder 
could  easily  be  fired  by  the  heat  of  the  sun's  rays  con- 


TPIE  ATMOSPHERE  LIKE  A  RATCHET.  243 

verged  by  passing  through  a  thick  water  lens  ;  the  drops 
upon  leaves  in  greenhouses  often  act  as  lenses,  and  cause 
the  sun  to  burn  the  leaves  upon  which  they  rest.  But 
with  regard  to  the  rays  of  heat  emanating  from  an  ob- 
scure source,  they  are  all  absorbed  by  a  layer  of  water 
less  than  the  20th  of  an  inch  in  thickness :  water  is 
opaque  to  such  rays,  and  cuts  them  off  almost  as  effectu- 
ally as  a  metallic  screen.  The  same  is  true  of  other 
liquids,  and  also  of  many  transparent  solids. 

Assuming  the  same  to  be  true  of  gaseous  bodies,  that 
they  also  intercept  the  obscure  rays  much  more  readily 
than  the  luminous  ones,  it  would  follow  that,  while  the 
sun's  rays  penetrate  our  atmosphere  with  freedom,  the 
change  which  they  undergo  in  warming  the  earth  de- 
prives them  in  a  measure  of  this  penetrating  power. 
They  can  reach  the  earth,  but  they  cannot  get  back; 
thus  the  atmosphere  acts  the  part  of  a  ratchet-wheel  in 
mechanics  ;  it  allows  of  motion  in  one  direction,  but  pre- 
vents it  in  the  other. 

De  Saussure,  Fourier,  M.  Pouillet,  and  Mr.  Hopkins 
have  developed  this  speculation,  and  drawn  from  it  con- 
sequences of  the  utmost  importance  ;  but  it  nevertheless 
rested  upon  a  basis  of  conjecture.  Indeed,  some  of  the 
eminent  men  above  named  deemed  its  truth  beyond  the 
possibility  of  experimental  verification.  Melloni  showed 
that  for  a  distance  of  18  or  20  feet  the  absorption  of  ob- 
scure rays  by  the  atmosphere  was  absolutely  inappre- 
ciable. Hence,  the  total  absorption  being  so  small  as  to 
elude  even  Melloni's  delicate  tests,  it  w,as  reasonable  to 
infer  that  differences  of  absorption,  if  such  existed  at  all, 
must  be  far  beyond  the  reach  of  the  finest  means  which 
we  could  apply  to  detect  them. 

This  exclusion  of  one  of  the  three  states  of  material 
aggregation  from  the  region  of  experiment  was,  however, 
by  no  means  satisfactory  ;  for  our  right  to  infer,  from  the 


244        DIFFERENCES   OF   ABSORPTION  BY   GASES. 

deportment  of  a  solid  or  a  liquid  towards  radiant  heat,  the 
deportment  of  a  gas,  is  by  no  means  evident.  In  both 
liquids  and  solids  we  have  the  molecules  closely  packed, 
and  more  or  less  chained  by  the  force  of  cohesion  ;  in 
gases,  on  the  contrary,  they  are  perfectly  free,  and  widely 
separated.  How  do  we  know  that  the  interception  of 
radiant  heat  by  liquids  and  solids  may  not  be  due  to 
an  arrangement  and  comparative  rigidity  of  their  parts, 
which  gases  do  not  at  all  share  ?  The  assumption  which 
took  no  note  of  such  a  possibility  seemed  very  insecure, 
and  called  for  verification. 

My  interest  in  this  question  was  augmented  by  the 
fact,  that  the  assumption  referred  to  lies,  as  will  be  seen, 
at  the  root  of  the  glacier  question.  I  therefore  en- 
deavoured to  fill  the  gap,  and  to  do  for  gases  and  vapours 
what  had  been  already  so  ably  done  for  liquids  and  solids 
by  Melioni.  I  tried  the  methods  heretofore  pursued,  and 
found  them  unavailing  ;  oxygen,  hydrogen,  nitrogen,  and 
atmospheric  air,  examined  by  such  methods,  showed 
no  action  upon  radiant  heat.  Nature  was  dumb,  but 
the  question  occurred,  "  Had  she  been  addressed  in  the 
proper  language  ?  "  If  the  experimentalist  is  convinced 
of  this,  he  will  rest  content  even  with  a  negative  ;  but  the 
absence  of  this  conviction  is  always  a  source  of  discom- 
fort, and  a  stimulus  to  try  again. 

The  principle  of  the  method  finally  applied  is  all  that 
can  here  be  referred  to  ;  and  it,  I  hope,  will  be  quite  in- 
telligible. Two  beams  of  heat,  from  two  distinct  sources, 
were  allowed  to  fall  upon  the  same  instrument,*  and  to 
contend  there  for  mastery.  When  both  beams  were  per- 
fectly equal,  they  completely  neutralized  each  other's  ac- 
tion ;  but  when  one  of  them  was  in  any  sensible  degree 
stronger  than  the  other,  the  predominance  of  the  former 
was  shown  by  the  instrument.  It  was  so  arranged  that 

*  The  opposite  faces  of  a  thermo-electric  pile. 


SELECTED   HEAT.  245 

one  of  the  conflicting  beams  passed  through  a  tube  which 
could  be  exhausted  of  air,  or  filled  with  any  gas ;  thus 
varying  at  pleasure  the  medium  through  which  it  passed. 
The  question  then  was,  supposing  the  two  beams  to  be 
equal  when  the  tube  was  filled  with  air,  will  the  ex- 
hausting of  the  tube  disturb  the  equality  ?  The  answer 
was  affirmative  ;  the  instrument  at  once  showed  that  a 
greater  quantity  of  heat  passed  through  the  vacuum  than 
through  the  air. 

The  experiment  was  so  arranged  that  the  effect  thus 
produced  was  very  large  as  measured  by  the  indications 
of  the  instrument.  But  the  action  of  the  simple  gases, 
oxygen,  hydrogen,  and  nitrogen,  was  incomparably  less 
than  that  produced  by  some  of  the  compound  gases,  while 
these  latter  again  differed  widely  from  each  other.  Ya- 
pours  exhibited  differences  of  equal  magnitude.  The 
experiments  indeed  proved  that  gaseous  bodies  varied 
among  themselves,  as  to  their  power  of  transmitting  ra- 
diant heat,  just  as  much  as  liquids  and  solids.  It  was 
in  the  highest  degree  interesting  to  observe  how  a  gas  or 
vapour  of  perfect  transparency,  as  regards  light,  acted 
like  an  opaque  screen  upon  the  heat.  To  the  eye,  the  gas 
within  the  tube  might  be  as  invisible  as  the  air  itself, 
while  to  the  radiant  heat  it  behaved  like  a  cloud  which  it 
was  almost  impossible  to  penetrate. 

Applying  the  same  method,  1  have  found  that  from  the 
sun,  from  the  electric  light,  or  from  the  lime-light,  a 
large  amount  of  heat  can  be  selected,  which  is  un- 
affected not  only  by  air,  but  by  the  most  energetic  gases 
that  experiment  has  revealed  to  me  ;  while  this  same 
heat,  when  it  has  its  quality  changed  by  being  rendered 
obscure,  is  powerfully  intercepted.  Thus  the  bold  and 
beautiful  speculation  above  referred  to  has  been  made  an 
experimental  fact ;  the  radiant  heat  of  the  sun  does  cer- 
tainly pass  through  the  atmosphere  to  the  earth  with 


246  POSSIBLE  HEAT  OF  NEPTUNE. 

greater  facility  than  the  radiant  heat  of  the  earth  can 
escape  into  space. 

It  is  probable  that,  were  the  earth  unfurnished  with  this 
atmospheric  swathing,  its  conditions  of  temperature  would 
be  such  as  to  render  it  uninhabitable  by  man ;  and  it  is 
also  probable  that  a  suitable  atmosphere  enveloping  the 
most  distant  planet  might  render  it,  as  regards  tempera- 
ture, perfectly  habitable.  If  the  planet  Neptune,  for 
example,  be  surrounded  by  an  atmosphere  which  permits 
the  solar  and  stellar  rays  to  pass  towards  the  planet,  but 
cuts  off  the  escape  of  the  warmth  which  they  excite,  it  is 
easy  to  see  that  such  an  accumulation  of  heat  may  at 
length  take  place  as  to  render  the  planet  a  comfortable 
habitation  for  beings  constituted  like  ourselves.* 

But  let  us  not  wander  too  far  from  our  own  concerns. 
Where  radiant  heat  is  allowed  to  fall  upon  an  absorbing 
substance,  a  certain  thickness  of  the  latter  is  always 
necessary  for  the  absorption.  Supposing  we  place  a  thin 
film  of  glass  before  a  source  of  heat,  a  certain  percentage 
of  the  heat  will  pass  through  the  glass,  and  the  remainder 
will  be  absorbed.  Let  the  transmitted  portion  fall  upon 
a  second  film  similar  to  the  first,  a  smaller  percentage 
than  before  will  be  absorbed.  A  third  plate  would  absorb 
still  less,  a  fourth  still  less ;  and,  after  passing  through  a 
sufficient  number  of  layers,  the  heat  would  be  so  sifted 
that  all  the  rays  capable  of  being  absorbed  by  glass  would 
be  abstracted  from  it.  Suppose  all  these  films  to  be  placed 
together  so  as  to  form  a  single  thick  plate  of  glass,  it  is 
evident  that  the  plate  must  act  upon  the  heat  which  falls 
upon  it,  in  such  a  manner  that  the  major  portion  is  ab- 
sorbed near  the  surface  at  which  the  heat  enters.  This 
has  been  completely  verified  by  experiment. 

Applying  this  to  the  heat  radiate^  from  the  earth,  it  is 

*  See  a  most  interesting  paper  on  this  subject  by  Mr.  Hopkins  in  the 
Cambridge  "Transactions,"  May,  1856. 


COLD  OF  UPPER  ATMOSPHERE.  247 

manifest  that  the  greatest  quantity  of  this  heat  will  be 
absorbed  by  the  lowest  atmospheric  strata.  And  here  we 
find  ourselves  brought,  by  considerations  apparently  re- 
mote, face  to  face  with  the  fact  upon  which  the  existence 
of  all  glaciers  depends,  namely,  the  comparative  coldness 
of  the  upper  regions  of  the  atmosphere.  The  sun's  rays 
can  pass  in  a  great  measure  through  these  regions  with- 
out heating  them;  and  the  earth's  rays,  which  they  might 
absorb,  hardly  reach  them  at  all,  but  are  intercepted  by 
the  lower  portions  of  the  atmosphere.* 

Another  cause  of  the  greater  coldness  of  the  higher 
atmosphere  is  the  expansion  of  the  denser  air  of  the  lower 
strata  when  it  ascends.  The  dense  air  makes  room  for 
itself  by  pushing  back  the  lighter  and  less  elastic  air  which 
surrounds  it ;  it  does  work,  and,  to  perform  this  work,  a 
certain  amount  of  heat  must  be  consumed.  It  is  the  con- 
sumption of  this  heat  —  its  absolute  annihilation  as  heat 
—  that  chills  the  expanded  air,  and  to  this  action  a  share 
of  the  coldness  of  the  higher  atmosphere  must  undoubt- 
edly be  ascribed.  A  third  cause  of  the  difference  of  tem- 
perature is  the  large  amount  of  heat  communicated,  by 
way  of  contact,  to  the  air  of  the  earth's  surface  ;  and  a 
fourth  and  final  cause  is  the  loss  endured  by  the  highest 
strata  through  radiation  into  space. 

*  See  M.  Pouillet's  important  Memoir  on  Solar  Radiation.    Taylor's  Sci- 
entific Memoirs,  vol.  iv.  p.  44. 


248  THE   SNOW-LINE. 


ORIGIN  OF   GLACIERS. 

(4.) 

HAVING  thus  accounted  for  the  greater  cold  of  the 
higher  atmospheric  regions,  its  consequences  are  next  to 
be  considered.  One  of  these  is,  that  clouds  formed  in  the 
lower  portions  of  the  atmosphere,  in  warm  and  temperate 
latitudes,  usually  discharge  themselves  upon  the  earth  as 
rain  ;  while  those  formed  in  the  higher  regions  discharge 
themselves  upon  the  mountains  as  snow.  The  snow  of 
the  higher  atmosphere  is  often  melted  to  rain  in  passing 
through  the  warmer  lower  strata  :  nothing  indeed  is  more 
common  than  to  pass,  in  descending  a  mountain,  from 
snow  to  rain ;  and  I  have  already  referred  to  a  case  of 
this  kind.  The  appearance  of  the  grassy  and  pine-clad 
Alps,  as  seen  from  the  valleys  after  a  wet  night,  is  often 
strikingly  beautiful ;  the  level  at  which  the  snow  turned 
to  rain  being  distinctly  marked  upon  the  slopes.  Above 
this  level  the  mountains  are  white,  while  below  it  they  are 
green.  The  eye  follows  this  snow-line  with  ease  along 
the  mountains,  and  when  a  sufficient  extent  of  country  is 
commanded  its  regularity  is  surprising. 

The  term  "  snow-line"  however,  which  has  been  here 
applied  to  a  local  and  temporary  phenomenon,  is  com- 
monly understood  to  mean  something  else.  In  the  case 
just  referred  to,  it  marked  the  place  where  the  supply  of 
solid  matter  from  the  upper  atmospheric  regions,  during 
a  single  fall,  was  exactly  equal  to  its  consumption ;  but 
the  term  is  usually  understood  to  mean  the  line  along 
which  the  quantity  of  snow  which  falls  annually  is  melted, 
and  no  more.  Below  this  line  each  year's  snow  is  com- 


MOUNTAINS  UNLOADED  BY  GLACIERS.  249 

pletely  cleared  away  by  the  summer  heat ;  above  it  a 
residual  layer  abides,  which  gradually  augments  in  thick- 
ness from  the  snow-line  upwards. 

Here  then  we  have  a  fresh  layer  laid  on  every  year ; 
and  it  is  evident  that,  if  this  process  continued  without 
interruption,  every  mountain  which  rises  above  the  snow- 
line  must  augment  annually  in  height ;  the  waters  of  the 
sea,  thus  piled,  in  a  solid  form,  upon  the  summits  of  the 
hills,  would  raise  the  latter  to  an  indefinite  elevation. 
But,  as  might  be  expected,  the  snow  upon  steep  mountain- 
sides frequently  slips  and  rolls  down  in  avalanches  into 
warmer  regions,  where  it  is  reduced  to  water.  A  com- 
paratively small  quantity  of  the  .snow  is,  however,  thus 
got  rid  of,  and  the  great  agent  which  Nature  employs  to 
relieve  her  overladen  mountains  is  the  glaciers. 

Let  us  here  avoid  an  error  which  may  readily  arise  out 
of  the  foregoing  reflections.  The  principal  region  of  clouds 
and  rain  and  snow  extends  only  to  a  limited  distance  up- 
wards in  the  atmosphere  ;  the  highest  regions  contain 
very  little  moisture,  and,  were  our  mountains  sufficiently 
lofty  to  penetrate  those  regions,  the  quantity  of  snow 
falling  upon  their  summits  would  be  too  trifling  to  resist 
the  direct  action  of  the  solar  rays.  These  would  annu- 
ally clear  the  summits  to  a  certain  level,  and  hence,  were 
our  mountains  high  enough,  we  should  have  a  superior, 
as  well  as  an  inferior,  snow-line  ;  the  region  of  perpetual 
snow  would  form  a  belt,  below  which,  in  summer,  snow- 
less  valleys  and  plains  would  extend,  and  above  which 
snowless  summits  would  rise. 


(5.) 

AT  its   origin  then  a  glacier  is  snow,  —  at  its  lower 
extremity  it  is  ice.     The  blue  blocks  that  arch  the  source 


250  WHITE  AND  BLUE  ICE. 

of  the  Arveiron  were  once  powdery  snow  upon  the  slopes 
of  the  Col  du  Ge*ant.  Could  our  vision  penetrate  into 
the  body  of  the  glacier,  we  should  find  that  the  change 
from  white  to  blue  essentially  consists  in  the  gradual 
expulsion  of  the  air  which  was  originally  entangled  in 
the  meshes  of  the  fallen  snow.  Whiteness  always  results 
from  the  intimate  and  irregular  mixture  of  air  and  a 
transparent  solid ;  a  crushed  diamond  would  resemble 
snow ;  if  we  pound  the  most  transparent  rock-salt  into 
powder  we  have  a  substance  as  white  as  the  whitest  culi- 
nary salt ;  and  the  colourless  glass  vessel  which  holds  the 
salt  would  also,  if  pounded,  give  a  powder  as  white  as  the 
salt  itself.  It  is  a  law  of  light,  that,  in  passing  from  one 
substance  to  another  possessing  a  different  power  of  re- 
fraction, a  portion  of  it  is  always  reflected.  Hence  when 
light  falls  upon  a  transparent  solid  mixed  with  air,  at 
each  passage  of  the  light  from  the  air  to  the  solid  and  from 
the  solid  to  the  air  a  portion  of  it  is  reflected  ;  and,  in 
the  case  of  a  powder,  this  reflection  occurs  so  frequently 
that  the  passage  of  the  light  is  practically  cut  off.  Thus, 
from  the  mixture  of  two  perfectly  transparent  substances, 
we  obtain  an  opaque  one  ;  from  the  intimate  mixture  of 
air  and  water  we  obtain  foam  ;  clouds  owe  their  opacity 
to  the  same  principle  ;  and  the  condensed  steam  of  a 
locomotive  casts  a  shadow  upon  the  fields  adjacent  to  the 
line,  because  the  sunlight  is  wasted  in  echos  at  the  innu- 
merable limiting  surfaces  of  water  and  air. 

The  snow  which  falls  upon  high  mountain-eminences 
has  often  a  temperature  far  below  the  freezing  point  of 
water.  Such  snow  is  dry,  and  if  it  always  continued 
so  the  formation  of  a  glacier  from  it  would  be  impos- 
sible. The  first  action  of  the  summer's  sun  is  to  raise 
the  temperature  of  the  superficial  snow  to  32°,  and  af- 
terwards to  melt  it.  The  water  thus  formed  percolates 
through  the  colder  mass  underneath,  and  this  I  take  to  be 


AIR-BUBBLES  IN  ICE.  251 

the  first  active  agency  in  expelling  the  air  entangled  in 
the  snow.  But  as  the  liquid  trickles  over  the  surfaces  of 
granules  colder  than  itself  it  is  partially  deposited  in  a 
solid  form  on  these  surfaces,  thus  augmenting  the  size  of 
the  granules,  and  cementing  them  together.  When  the 
mass  thus  formed  is  examined,  the  air  within  it  is  found  as 
round  bubbles.  Now  it  is  manifest  that  the  air  caught  in 
the  irregular  interstices  of  the  snow  can  have  no  tendency 
to  assume  this  form  so  long  as  the  snow  remains  solid  ; 
but  the  process  to  which  I  have  referred  —  the  saturation 
of  the  lower  portions  of  the  snow  by  the  water  produced 
by  the  melting  of  the  superficial  portions  —  enables  the 
air  to  form  itself  into  globules,  and  to  give  the  ice  of 
the  neve  its  peculiar  character.  Thus  we  see  that,  though 
the  sun  cannot  get  directly  at  the  deeper  portions  of  the 
snow,  by  liquefying  the  upper  layer  he  charges  it  with 
heat,  and  makes  it  his  messenger  to  the  cold  subjacent 
mass. 

The  frost  of  the  succeeding  winter  may,  I  think,  or  may 
not,  according  to  circumstances,  penetrate  through  this 
layer,  and  solidify  the  water  which  it  still  retains  in  its 
interstices.  If  the  winter  set  in  with  clear  frosty  wea- 
ther, the  penetration  will  probably  take  place ;  but  if 
heavy  snow  occur  at  the  commencement  of  winter,  thus 
throwing  a  protective  covering  over  the  neve,  freezing  to 
any  great  depth  may  be  prevented.  Mr.  Huxley's  idea 
seems  to  be  quite  within  the  range  of  possibility,  that 
water-cells  may  be  transmitted  from  the  origin  of  the 
glacier  to  its  end,  retaining  their  contents  always  liquid. 

It  was  formerly  supposed,  and  is  perhaps  still  supposed 
by  many,  that  the  snow  of  the  mountains  is  converted  into 
the  ice  of  the  glacier  by  the  process  of  saturation  and 
freezing  just  indicated.  But  the  frozen  layer  would  not  yet 
resemble  glacier  ice  ;  it  is  only  at  the  deeper  portions  of 
the  nevS  that  we  find  an  approximation  to  the  true  ice  of 


252  SNOW  PRESSED   TO   ICE. 

the  glacier.  This  brings  us  to  the  second  great  agent  in 
the  process  of  glacification,  namely,  pressure.  The  ice  of 
the  neve  at  32°  may  be  squeezed  or  crushed  with  extreme 
facility ;  and  if  the  force  be  applied  slowly  and  with  cau- 
tion, the  yielding  of  the  mass  may  be  made  to  resemble 
the  yielding  of  a  plastic  body.  In  the  depths  of  the  neve", 
where  each  portion  of  the  ice  is  surrounded  by  a  resistant 
mass,  rude  crushing  is  of  course  out  of  the  question. 
The  layers  underneath  yield  with  extreme  slowness  to 
the  pressure  of  the  mass  above  them  ;  they  are  squeezed, 
but  not  rudely  fractured  ;  and  even  should  rude  fracture 
occur,  the  ice,  as  shall  subsequently  be  shown,  possesses 
the  power  of  restoring  its  own  continuity.  Thus,  then, 
the  lower  portions  of  the  nevS  are  removed  by  pressure 
more  and  more  from  the  condition  of  snow,  the  air-bubbles 
which  give  to  the  neve-ice  its  whiteness  are  more  and 
more  expelled,  and  this  process,  continued  throughout  the 
entire  glacier,  finally  brings  the  ice  to  that  state  of  mag- 
nificent transparency  which  we  find  at  the  termination 
of  the  glacier  of  Rosenlaui  and  elsewhere.  This  is  all 
capable  of  experimental  proof.  The  Messrs.  Schlagint- 
weit  compressed  the  snow  of  the  ne've'  to  compact  ice  ;  and 
I  have  myself  frequently  obtained  slabs  of  ice  from  snow 
in  London. 


LONG  WAVES  MOST  ABSORBED.  253 

COLOUR  OF   WATER  AND   ICE. 
(6.) 

THE  sun  is  continually  sending  forth  waves  of  different 
lengths,  all  of  which  travel  with  the  same  velocity  through 
the  ether.  When  these  waves  enter  a  prism  of  glass  they 
are  retarded,  but  in  different  degrees.  The  shorter  waves 
suffer  the  greatest  retardation,  and  in  consequence  of  this 
are  mostly  deflected  from  their  straight  course.  It  is  this 
property  which  enables  us  to  separate  one  from  the  other 
in  the  solar  spectrum,  and  this  separation  proves  that  the 
waves  are  by  no  means  inextricably  entangled  with  each 
other,  but  that  they  travel  independently  through  space. 

In  consequence  of  this  independence,  the  same  body 
may  intercept  one  system  of  waves  while  it  allows  another 
to  pass :  on  this  quality,  indeed,  depend  all  the  phenomena 
of  colour.  A  red  glass,  for  example,  is  red  because  it 
is  so  constituted  that  it  destroys  the  shorter  waves  which 
produce  the  other  colours,  and  transmits  only  the  waves 
which  produce  red.  I  may  remark,  however,  that  scarcely 
any  glass  is  of  a  pure  colour  ;  along  with  the  predominant 
waves,  some  of  the  other  waves  are  permitted  to  pass. 
The  colours  of  flowers  are  also  very  impure  ;  in  fact,  to 
get  pure  colours  we  must  resort  to  a  delicate  prismatic 
analysis  of  white  light. 

It  has  already  been  stated  that  a  layer  of  water  less 
than  the  twentieth  of  an  inch  in  thickness  suffices  to  stop 
and  destroy  all  waves  of  radiant  heat  emanating  from  an 
obscure  source.  The  longer  waves  of  the  obscure  heat 
cannot  get  through  water,  and  I  find  that  all  transparent 
compounds  which  contain  hydrogen  are  peculiarly  hostile 
to  the  longer  undulations.  It  is,  I  think,  the  presence  of 


254      FINAL  COLOUR  OF  ICE  AND  WATER  BLUE. 

this  element  in  the  humours  of  the  eye  which  prevents  the 
extra  red  rays  of  the  solar  spectrum  from  reaching  the 
retina.  It  is  interesting  to  observe  that  while  bisulphide 
of  carbon,  chloride  of  phosphorus,  and  other  liquids  which 
contain  no  hydrogen,  permit  a  large  portion  of  the  rays 
emanating  from  an  iron  or  copper  ball,  at  a  heat  below 
redness,  to  pass  through  them  with  facility,  the  same 
thickness  of  substances  equally  transparent,  but  which 
contain  hydrogen,  such  as  ether,  alcohol,  water,  or  the 
vitreous  humour  of  the  eye  of  an  ox,  completely  inter- 
cepts these  obscure  rays.  The  same  is  true  of  solid  bodies  ; 
a  very  slight  thickness  of  those  which  contain  hydrogen 
offers  an  impassable  barrier  to  all  rays  emanating  from  a 
non-luminous  source.*  But  the  heat  thus  intercepted  is 
by  no  means  lost ;  its  radiant  form  merely  is  destroyed. 
Its  waves  are  shivered  upon  the  particles  of  the  body,  but 
.they  impart  warmth  to  it,  while  the  heat  which  retains  its 
radiant  form  contributes  in  no  way  to  the  warmth  of  the 
body  through  which  it  passes. 

Water  then  absorbs  all  the  extra  red  -rays  of  the  sun, 
and  if  the  layer  be  thick  enough  it  invades  the  red  rays 
themselves.  Thus  the  greater  the  distance  the  solar  beams 
travel  through  pure  water,  the  more  are  they  deprived  of 
those  components  which  lie  at  the  red  end  of  the  spec- 
trum. The  consequence  is,  that  the  light  finally  trans- 
mitted by  the  water,  and  which  gives  to  it  its  colour,  is 
blue. 

I  find  the  following  mode  of  examining  the  colour  of 
water  both  satisfactory  and  convenient.  A  tin  tube,  fifteen 
feet  long  and  three  inches  in  diameter,  has  its  two  ends 
stopped  securely  by  pieces  of  colourless  plate  glass.  It 

*  What  is  here  stated  regarding  hydrogen  is  true  of  all  the  liquids  and 
solids  which  have  hitherto  been  examined,  —  but  whether  any  exceptions 
occur,  future  experience  must  determine.  It  is  only  when  in  combination 
that  it  exhibits  this  impermeability  to  the  obscure  rays. 


EXPERIMENT.  255 

is  placed  in  a  horizontal  position,  and  pure  water  is  poured 
into  it  through  a  small  lateral  pipe,  until  the  liquid  reaches 
half-way  up  the  glasses  at  the  ends ;  the  tube  then  holds 
a  semi-cylinder  of  water  and  a  semi-cylinder  of  air.  A 
white  plate,  or  a  sheet  of  white  paper,  well  illuminated,  is 
then  placed  at  a  little  distance  from  one  end  of  the  tube, 
and  is  looked  at  through  the  tube.  Two  semicircular 
spaces  are  then  seen,  one  by  the  light  which  has  passed 
through  the  air,  the  other  by  the  light  which  has  passed 
through  the  water  ;  and  their  proximity  furnishes  a  means 
of  comparison,  which  is  absolutely  necessary  in  experiments 
of  this  kind.  It  is  always  found  that,  while  the  former 
semicircle  remains  white,  the  latter  one  is  vividly  coloured.* 

When  the  beam  from  an  electric  lamp  is  sent  through 
this  tube,  and  a  convex  lens  is  placed  at  a  suitable  dis- 
tance from  its  most  distant  end,  a  magnified  image  of  the 
coloured  and  uncoloured  semicircles  may  be  projected 
upon  a  screen.  Tested  thus,  I  have  sometimes  found, 
after  rain,  the  ordinary  pipe-water  of  the  Royal  Institution 
quite  opaque  ;  while,  under  other  circumstances,  I  have 
found  the  water  of  a  clear  green.  The  pump-water  of  the 
Institution  thus  examined  exhibits  a  rich  sherry  colour, 
while  distilled  water  is  blue-green. 

The  blueness  of  the  Grotto  of  Capri  is  due  to  the  fact 
that  the  light  which  enters  it  has  previously  traversed  a 
great  depth  of  clear  water.  According  to  Bunsen's  ac- 
count, the  langs,  or  cisterns  of  hot  water,  in  Iceland  must 
be  extremely  beautiful.  The  water  contains  silica  in 
solution,  which,  as  the  walls  of  the  cistern  arose,  was 
deposited  upon  them  in  fantastic  incrustations.  These, 
though  white,  when  looked  at  through  the  water  appear 
of  a  lovely  blue,  which  deepens  in  tint  as  the  vision 
plunges  deeper  into  the  liquid. 

*  In  my  own  experiments  I  have  never  yet  been  able  to  obtain  a  pure  blue, 
the  nearest  approach  to  it  being  a  blue-green. 


256  ICE  OPAQUE   TO  KADIANT  HEAT. 

Ice  is  a  crystal  formed  from  this  blue  liquid,  the  colour 
of  which  it  retains.  Ice  is  the  most  opaque  of  transparent 
solids  to  radiant  heat,  as  water  is  the  most  opaque  of 
liquids.  According  to  Melloni,  a  plate  of  ice  one  twenty- 
fifth  of  an  inch  thick,  which  permits  the  rays  of  light  to 
pass  without  sensible  absorption,  cuts  off  94  per  cent,  of 
the  rays  of  heat  issuing  from  a  powerful  oil  lamp,  99  J  per 
cent,  of  the  rays  issuing  from  incandescent  platinum,  and 
the  whole  of  the  rays  issuing  from  an  obscure  source. 
The  above  numbers  indicate  how  large  a  portion  of  the 
rays  emitted  by  our  artificial  sources  of  light  is  obscure. 

When  the  rays  of  light  pass  through  a  sufficient  thickness 
of  ice,  the  longer  waves  are,  as  in  the  case  of  water,  more 
and  more  absorbed,  and  the  final  colour  of  the  substance 
is  therefore  blue.  But  when  the  ice  is  filled  with  minute 
air-bubbles,  though  we  should  loosely  call  it  white,  it  may 
exhibit,  even  in  small  pieces,  a  delicate  blue  tint.  This, 
I  think,  is  due  to  the  frequent  interior  reflection  which 
takes  place  at  the  surfaces  of  the  air-cells ;  so  that  the 
light  which  reaches  the  eye  from  the  interior  may,  in  con- 
sequence of  its  having  been  reflected  hither  and  thither, 
really  have  passed  through  a  considerable  thickness  of  ice. 
The  same  remark,  as  we  have  already  seen,  applies  to  the 
delicate  colour  of  the  newly  fallen  snow. 


NEWTON'S   HYPOTHESIS.  257 


COLOURS  OF  THE   SKY. 

(7.) 

IN  treating  of  the  Colours  of  Thin  Plates  we  found  that 
a  certain  thickness  was  necessary  to  produce  blue,  while 
a  greater  thickness  was  necessary  for  red.  With  that 
wonderful  power  of  generalization  which  belonged  to  him, 
Newton  thus  applies  this  apparently  remote  fact  to  the 
blue  of  the  sky :  —  "  The  blue  of  the  first  order,  though 
very  faint  and  little,  may  possibly  be  the  colour  of  some 
substances,  and  particularly  the  azure  colour  of  the  skies 
seems  to  be  of  this  order.  For  all  vapours,  when  they 
begin  to  condense  and  coalesce  into  small  parcels,  become 
first  of  that  bigness  whereby  such  an  azure  is  reflected, 
before  they  can  constitute  clouds  of  other  colours.  And 
so,  this  being  the  first  colour  which  vapours  begin  to 
reflect,  it  ought  to  be  the  colour  of  the  finest  and  most 
transparent  skies,  in  which  vapours  are  not  arrived  at 
that  grossness  requisite  to  reflect  other  colours,  as  we 
find  it  is  by  experience." 

M.  Clausius  has  written  a  most  interesting  paper,  in 
which  he  endeavours  to  show  that  the  minute  particles  of 
water  which  are  supposed  by  Newton  to  reflect  the  light, 
cannot  be  little  globes  entirely  composed  of  water,  but 
bladders  or  hollow  spheres  :  the  vapour  must  be  in  what 
is  generally  termed  the  vesicular  state.  He  was  followed 
by  M.  Briicke,  whose  experiments  prove  that  the  sus- 
pended particles  may  be  so  small  that  the  reasoning  of 
M.  Clausius  may  not  apply  to  them. 

But  why  assume  the  existence  of  such  particles  at  all  ? 
—  why  not  assume  that  the  colour  of  the  air  is  blue,  and 
renders  the  light  of  the  sun  blue,  after  the  fashion  of  a 
17 


258  GOETHE'S   HYPOTHESIS. 

blue  glass  or  a  solution  of  the  sulphate  of  copper  ?  I 
have  already  referred  to  the  great  variation  which  the 
colour  of  the  firmament  undergoes  in  the  Alps,  and  have 
remarked  that  this  seems  to  indicate  that  the  blue  de- 
pends upon  some  variable  constituent  of  the  atmosphere. 
Further,  we  find  that  the  blue  light  of  the  sky  is  reflected 
light ;  and  there  must  be  something  in  the  atmosphere 
capable  of  producing  this  reflection  ;  but  this  thing,  what* 
ever  it  is,  produces  another  effect  which  the  blue  glass  or 
liquid  is  unable  to  produce.  These  transmit  blue  light, 
whereas,  when  the  solar  beams  have  traversed  a  great 
length  of  air,  as  in  the  morning  or  the  evening,  they  are 
yellow,  or  orange,  or  even  blood-red,  according  to  the 
state  of  the  atmosphere :  —  the  transmitted  light  and  the 
reflected  light  of  the  atmosphere  are  then  totally  different 
in  colour. 

Goethe,  in  his  celebrated  "  Farbenlehre,"  gives  a  theory 
of  the  colour  of  the  sky,  and  has  illustrated  it  by  a  series 
of  striking  facts.  He  assumed  two  principles  in  the  uni- 
verse —  Light  and  Darkness  —  and  an  intermediate  stage 
of  Turbidity.  When  the  darkness  is  seen  through  a 
turbid  medium  on  which  the  light  falls,  the  medium  ap- 
pears blue  ;  when  the  light  itself  is  viewed  through  such 
a  medium,  it  is  yellow,  or  orange,  or  ruby-red.  This  he 
applies  to  the  atmosphere,  which  sends  us  blue  light,  or 
red,  according  as  the  darkness  of  infinite  space,  or  the 
bright  surface  of  the  sun,  is  regarded  through  it. 

As  a  theory  of  colours  Goethe's  work  is  of  no  value,  but 
the  facts  which  he  has  brought  forward  in  illustration  of 
the  action  of  turbid  media  are  in  the  highest  degree  inter- 
esting. He  refers  to  the  blueness  of  distant  mountains,  of 
smoke,  of  the  lower  part  of  the  flame  of  a  candle  (which 
if  looked  at  with  a  white  surface  behind  it  completely  dis- 
appears) ,  of  soapy  water,  and  of  the  precipitates  of  various 
resins  in  water.  One  of  his  anecdotes  in  connexion  with 


SUSPENDED  PARTICLES.  259 

this  subject  is  extremely  curious  and  instructive.  The 
portrait  of  a  very  dignified  theologian  having  suffered 
from  dirt,  it  was  given  to  a  painter  to  be  cleaned.  The 
clergyman  was  drawn  in  a  dress  of  black  velvet,  over 
which  the  painter,  in  the  first  place,  passed  his  sponge.  To 
his  astonishment  the  black  velvet  changed  to  the  colour 
of  blue  plush,  and  completely  altered  the  aspect  of  its 
wearer.  Goethe  was  informed  of  the  fact ;  the  experi- 
ment was  repeated  in  his  presence,  and  he  at  once  solved 
it  by  reference  to  his  theory.  The  varnish  of  the  picture 
when  mixed  with  the  water  formed  a  turbid  medium,  and 
the  black  coat  seen  through  it  appeared  blue ;  when  the 
water  evaporated,  the  coat  resumed  its  original  aspect. 

With  regard  to  the  real  explanation  of  these  effects,  it 
may  be  shown,  that,  if  a  beam  of  white  light  be  sent 
through  a  liquid  which  contains  extremely  minute  parti- 
cles in  a  state  of  suspension,  the  short  waves  are  more 
copiously  reflected  by  such  particles  than  the  long  ones ; 
blue,  for  example,  is  more  copiously  reflected  than  red. 
This  may  be  shown  by  various  fine  precipitates,  but  the 
best  is  that  of  B'riicke.  We  know  that  mastic  and  various 
resins  are  soluble  in  alcohol,  and  are  precipitated  when 
the  solution  is  poured  into  water :  Eau  de  Cologne,  for 
example,  produces  a  white  precipitate  when  poured  into 
water.  If  however  this  precipitate  be  sufficiently  diluted, 
it  gives  the  liquid  a  bluish  colour  by  reflected  light. 
Even  when  the  precipitate  is  very  thick  and  gross,  and 
floats  upon  the  liquid  like  a  kind  of  curd,  its  under  por- 
tions often  exhibit  a  fine  blue.  To  obtain  particles  of  a 
proper  size,  Briicke  recommends  1  gramme  of  colourless 
mastic  to  be  dissolved  in  87  grammes  of  alcohol,  and 
dropped  into  a  beaker  of  water,  which  is  kept  in  a  state 
of  agitation.  In  this  way  a  blue  resembling  that  of  the 
firmament  may  be  produced.  It  is  best  seen  when  a  black 
cloth  is  placed  behind  the  glass ;  but  in  certain  positions 


260  THE   SUN  THROUGH  LONDON   SMOKE. 

this  blue  liquid  appears  yellow;  and  these  are  the  positions 
when  the  transmitted  light  reaches  the  eye.  It  is  evident 
that  this  change  of  colour  must  necessarily  exist ;  for  the 
blue  being  partially  withdrawn  by  more  copious  reflec- 
tion, the  transmitted  light  must  partake  more  or  less  of 
the  character  of  the  complementary  colour ;  though  it  does 
not  follow  that  they  should  be  exactly  complementary  to 
each  other. 

When  a  long  tube  is  filled  with  clear  water,  the  colour 
of  the  liquid,  as  before  stated,  shows  itself  by  transmitted 
light.  The  effect  is  very  interesting  when  a  solution  of 
mastic  is  permitted  to  drop  into  such  a  tube,  and  the  fine 
precipitate  to  diffuse  itself  in  the  water.  The  blue-green 
of  the  liquid  is  first  neutralized,  and  a  yellow  colour 
shows  itself ;  on  adding  more  of  the  solution,  the  colour 
passes  from  yellow  to  orange,  and  from  orange  to  blood- 
red.  With  a  cell  an  inch  and  a  half  in  width,  containing 
water,  into  which  the  solution  of  mastic  is  suffered  to  drop, 
the  same  effect  may  be  obtained.  If  the  light  of  an 
electric  lamp  be  caused  to  form  a  clear  sunlike  disk  upon 
a  white  screen,  the  gradual  change  of  this  light  by  aug- 
mented precipitation  into  deep,  glowing  red,  resembling 
the  colour  of  the  sun  when  seen  through  fine  London 
smoke,  is  exceedingly  striking.  Indeed  the  smoke  acts,  in 
some  measure,  the  part  of  our  finely-suspended  matter. 

By  such  means  it  is  possible  to  imitate  the  phenomena 
of  the  firmament ;  we  can  produce  its  pure  blue,  and  cause 
it  to  vary  as  in  nature.  The  milkiness  which  steals  over 
the  heavens,  and  enables  us  to  distinguish  one  cloudless 
day  from  another,  can  be  produced  with  the  greatest  ease. 
The  yellow,  orange,  and  red  light  of  the  morning  and 
evening  can  also  be  obtained :  indeed,  the  effects  are  so 
strikingly  alike  as  to  suggest  a  common  origin  —  that  the 
colours  of  the  sky  are  due  to  minute  particles  diffused 
through  the  atmosphere.  These  particles  are  doubtless 


MORNING  AND  EVENING  RED.  261 

the  condensed  vapour  of  water,  and  its  variation  in  qual- 
ity and  amount  enables  us  to  understand  the  variability  of 
the  firmamental  blue,  and  of  the  morning  and  the  even- 
ing red.  Professor  Forbes,  moreover,  has  made  the  inter- 
esting observation  that  the  steam  of  a  locomotive,  at  a 
certain  stage  of  its  condensation,  is  blue  or  red  according 
as  it  is  viewed  by  reflected  or  transmitted  light. 

These  considerations  enable  us  to  account  for  a  num- 
ber of  facts  of  common  occurrence.  Thin  milk,  when 
poured  upon  a  black  surface,  appears  bluish.  The  milk 
is  colourless ;  that  is,  its  blueness  is  not  due  to  absorption, 
but  to  a  separation  of  the  light  by  the  particles  suspended 
in  the  liquid.  The  juices  of  various  plants  owe  their 
blueness  to  the  same,  cause ;  but  perhaps  the  most  curious 
illustration  is  that  presented  by  a  blue  eye.  Here  we 
have  no  true  colouring-matter,  no  proper  absorption  ;  but 
we  look  through  a  muddy  medium  at  the  black  choroid 
coat  within  the  eye,  and  the  medium  appears  blue.* 

Is  it  not  probable  that  this  action  of  finely-divided  mat- 
ter may  have  some  influence  on  the  colour  of  some  of  the 
Swiss  lakes,  —  as  that  of  Geneva  for  example  ?  This  lake 
is  simply  an  expansion  of  the  River  Rhone,  which  rushes 
from  the  end  of  the  Rhone  glacier,  as  the  Arveiron  does 
from  the  end  of  the  Mer  de  Glace.  Numerous  other 
streams  join  the  Rhone  right  and  left  during  its  down- 
ward course  ;  and  these  feeders,  being  almost  wholly  de- 
rived from  glaciers,  join  the  Rhone  charged  with  the 
finer  matter  which  these  in  their  motion  have  ground 
from  the  rocks  over  which  they  have  passed.  But  the 
glaciers  must  grind  the  mass  beneath  them  to  particles 
of  all  sizes,  and  I  cannot  help  thinking  that  the  finest  of 
them  must  remain  suspended  in  the  lake  throughout  its 
entire  length.  Faraday  has  shown  that  a  precipitate  of 
gold  may  require  months  to  sink  to  the  bottom  of  a  bottle 

*  Helmholtz,  "  Das  Sehen  des  Menschen." 


262  COLOUR  OF  SWISS  LAKES. 

not  more  than  five  inches  high,  and  in  all  probability  it 
would  require  ages  of  calm  subsidence  to  bring  all  the 
particles  which  the  Lake  of  Geneva  contains  to  its  bot- 
tom. It  seems  certainly  worthy  of  examination  whether 
such  particles  suspended  in  the  water  contribute  to  the 
production  of  that  magnificent  blue  which  has  excited 
the  admiration  of  all  who  have  seen  it  under  favourable 
circumstances. 


LATERAL  MORAINES.  263 


THE    MORAINES. 

(8.) 

THE  surface  of  the  glacier,  does  not  long  retain  the 
shining  whiteness  of  the  snow  from  which  it  is  derived. 
It  is  flanked  by  mountains  which  are  washed  by  rain, 
dislocated  by  frost,  riven  by  lightning,  traversed  by  ava- 
lanches, and  swept  by  storms.  The  lighter  debris  is  scat- 
tered by  the  winds  far  and  wide  over  the  glacier,  sullying 
the  purity  of  its  surface.  Loose  shingle  rattles  at  inter- 
vals down  the  sides  of  the  mountains,  and  falls  upon  the 
ice  where  it  touches  the  rocks.  Large  rocks  are  continu- 
ally let  loose,  which  come  jumping  from  ledge  to  ledge,  the 
cohesion  of  some  being  proof  against  the  shock  which  they 
experience  ;  while  others,  when  they  hit  the  rocks,  burst 
like  bomb-shells,  and  shower  their  fragments  upon  the  ice. 

Thus  the  glacier  is  incessantly  loaded  along  its  borders 
with  the  ruins  of  the  mountains  which  limit  it ;  and  it  is 
evident  that  the  quantity  of  rock  and  rubbish  thus  cast 
upon  the  glacier  depends  upon  the  character  of  the  ad- 
jacent mountains.  Where  the  summits  are  bare  and 
friable,  we  may  expect  copious  showers ;  where  they  are 
resistant,  and  particularly  where  they  are  protected  by  a 
covering  of  ice  and  snow,  the  quantity  will  be  small.  As 
the  glacier  moves  downward,  it  carries  with  it  the  load 
deposited  upon  it.  Long  ridges  of  debris  thus  flank  the 
glacier,  and  these  ridges  are  called  lateral  moraines. 
Where  two  tributary  glaciers  join  to  form  a  trunk-glacier, 
their  adjacent  lateral  moraines  are  laid  side  by  side  at 
the  place  of  confluence,  thus  constituting  a  ridge  which 
runs  along  the  middle  of  the  trunk-glacier,  and  which  is 


264  MEDIAL  AND  TERMINAL  MORAINES. 

called  a  medial  moraine.  The  rocks  and  debris  carried 
down  by  the  glacier  are  finally  deposited  at  its  lower  ex- 
tremity, forming  there  a  terminal  moraine. 

It  need  hardly  be  stated,  that  the  number  of  medial 
moraines  is  only  limited  by  the  number  of  branch  glaciers. 
If  a  glacier  have  but  two  branches,  it  will  have  only  one 
medial  moraine ;  if  it  have  three  branches,  it  will  have 
two  medial  moraines  ;  if  n^  branches,  it  will  have  n  —  1 
medial  moraines.  The  number  of  medial  moraines,  in 
short,  is  always  one  less  than  the  number  of  branches. 
A  glance  at  the  annexed  figure  will  reveal  the  manner 
in  which  the  lateral  moraines  of  the  Mer  de  Glace  unite 
to  form  medial  ones.  (See  Fig.  19.) 

When  a  glacier  diminishes  in  size  it  leaves  its  lateral 
moraines  stranded  on  the  flanks  of  the  valleys.  Succes- 
sive shrinkings  may  thus  occur,  and  have  occurred  at 
intervals  of  centuries ;  and  a  succession  of  old  lateral 
moraines,  such  as  many  glacier  valleys  exhibit,  is  the  con- 
sequence. The  Mer  de  Glace,  for  example,  has  its  old 
lateral  moraines,  which  run  parallel  with  its  present  ones. 
The  glacier  may  also  diminish  in  length  at  distant  inter- 
vals ;  the  result  being  a  succession  of  more  or  less  con- 
centric terminal  moraines.  In  front  of  the  Rhone  glacier 
we  have  six  or  seven  such  moraines,  and  the  Mer  de  Glace 
also  possesses  a  series  of  them. 

Let  us  now  consider  the  effect  produced  by  a  block  of 
stone  upon  the  surface  of  a  glacier.  The  ice  around  it 
receives  the  direct  rays  of  the  sun,  and  is  acted  on  by  the 
warm  air ;  it  is  therefore  constantly  melting.  The  stone 
also  receives  the  solar  beams,  is  warmed,  and  transmits 
its  heat,  by  conduction,  to  the  ice  beneath  it.  If  the 
heat  thus  transmitted  to  the  ice  through  the  stone  be  less 
than  an  equal  space  of  the  surrounding  ice  receives,  it  is 
manifest  that  the  ice  around  the  stone  will  waste  more 
quickly  than  that  beneath  it,  and  the  consequence  is,  that, 


MORAINES  OF  THE  MER  DE  GLACE. 
Fig.  19. 


GLACIER  TABLES  ACCOUNTED  FOR.  265 

as  the  surface  sinks,  it  leaves  behind  it  a  pillar  of  ice,  on 
which  the  block  is  elevated.  If  the  stone  be  wide  and  flat, 
it  may  rise  to  a  considerable  height,  and  in  this  position 
it  constitutes  what  is  called  a  glacier-ta&fe. 

Almost  all  glaciers  present  examples  of  such  tables ;  but 
no  glacier  with  which  I  am  acquainted  exhibits  them  in 
greater  number  and  perfection  than  the  Unteraar  glacier, 
near  the  Grimsel.  Yast  masses  of  granite  are  thus  poised 
aloft  on  icy  pedestals ;  but  a  limit  is  placed  to  their  ex- 
altation by  the  following  circumstance.  The  sun  plays 
obliquely  upon  the  table  all  day ;  its  southern  extremity 
receives  more  heat  than  its  northern,  and  the  conse- 
quence is,  that  it  dips  toward  the  south.  Strictly  speak- 
ing, the  plane  of  the  dip  rotates  a  little  during  the  day, 
being  a  little  inclined  towards  the  east  in  the  morning, 
north  and  south  a  little  after  noon,  and  inclined  towards 
the  west  in  the  evening ;  so  that,  theoretically  speaking,  the 
block  is  a  sun-dial,  showing  by  its  position  the  hour  of  the 
day.  This  rotation  is,  however,  too  small  to  be  sensible, 
and  hence  the  dip  of  the  stones  upon  a  glacier  sufficiently 
exposed  to  the  sunlight ,  enables  us  at  any  time  to  draw  the 
meridian  line  along  its  surface.  The  inclination  finally 
becomes  so  great  that  the  block  slips  off  its  pedestal,  and 
begins  to  form  another,  while  the  one  which  it  originally 
occupied  speedily  disappears,  under  the  influence  of  sun 
and  air.  Fig.  20  represents  a  typical  section  of  a  glacier- 
table,  the  sun's  rays  being  supposed  to  fall  in  the  direc- 
tion of  the  shading  lines. 

Stones  of  a  certain  size  are  always  lifted  in  the  way 
described.  A  considerable  portion  of  the  heat  which  a 
large  block  receives  is  wasted  by  radiation,  and  by  com- 
munication to  the  air,  so  that  the  quantity  which  reaches 
the  ice  beneath  is  trifling.  Such  a  mass  is,  of  course,  a 
protector  of  the  ice  beneath  it.  But  if  the  stone  be  small, 
and  dark  in  colour,  it  absorbs  the  heat  with  avidity,  com- 


266 


TY£E   "TABLE." 


municates  it  quickly  to  the  ice  with  which  it  is  in  contact, 
and  consequently  sinks  in  the  ice.  This  is  also  the  case 
with  bits  of  dirt  and  the  finer  fragments  of  debris  ;  they 
sink  in  the  glacier.  Sometimes,  however,  a  pretty  thick 


Fig.  20. 

layer  of  sand  is  washed  over  the  ice  from  the  moraines,  or 
from  the  mountain-sides  ;  and  such  sand-layers  give  birth 
to  ice-cones,  which  grow  to  peculiarly  grand  dimensions 
on  the  Lower  Aar  glacier.  I  say  "  grow,"  but  the  truth, 
of  course,  is,  that  the  surrounding  ice  wastes,  while  the 
portion  underneath  the  sand  is  so  protected  that  it  re- 
mains as  an  eminence  behind.  At  first  sight,  these  sand- 
covered  cones  appear  huge  heaps  of  dirt,  but  on  examina- 
tion they  are  found  to  be  cones  of  ice,  and  that  the  dirt 
constitutes  merely  a  superficial  covering. 

Turn  we  now  to  the  moraines.  Protecting,  as  they  do,  the 
ice  from  waste,  they  rise,  as  might  be  expected,  in  vast  ridges 
above  the  general  surface  of  the  glacier.  In  some  cases  the 
surrounding  mass  has  been  so  wasted  as  to  leave  the  spines 
of  ice  which  support  the  moraines  forty  or  fifty  feet  above 
the  general  level  of  the  glacier.  I  should  think  the  moraines 


MORAINES  ENGULFED  AND  DISGORGED.  267 

of  the  Mer  de  Glace  about  the  Tacul  rise  to  this  height. 
But  lower  down,  in  the  neighbourhood  of  the  Echelets, 
these  high  ridges  disappear,  and  nought  remains  to  mark 
the  huge  moraine  but  a  strip  of  dirt,  and  perhaps  a  slight 
longitudinal  protuberance  on  the  surface  of  the  glacier. 
How  have  the  blocks  vanished  that  once  loaded  the 
moraines  near  the  Tacul  ?  They  have  been  swallowed  in 
the  crevasses  which  intersect  the  moraines  lower  down ; 
and  if  we  could  examine  the  ice  at  the  Echelets  we  should 
find  the  engulfed  rocks  in  the  body  of  the  glacier. 

Cases  occur,  wherein  moraines,  after  having  been 
engulfed,  and  hidden  for  a  time,  are  again  entirely 
disgorged  by  the  glacier.  Two  moraines  run  along  the 
basin  of  the  Talefre,  one  from  the  Jar  din,  the  other  from 
an  adjacent  promontory,  proceeding  parallel  to  each  other 
towards  the  summit  of  the  great  ice-fall.  Here  the  ice  is 
riven,  and  profound  chasms  are  formed,  in  which  the 
blocks  and  shingle  of  the  moraines  disappear.  Through- 
out the  entire  ice-fall  the  only  trace  of  the  moraines  is  a 
broad  dirt-streak,  which  the  eye  may  follow  along  the  cen- 
tre of  the  fall,  with  perhaps  here  and  there  a  stone  which 
has  managed  to  rise  from  its  frozen  sepulchre.  But  the 
ice  wastes,  and  at  the  base  of  the  fall  large  masses  of 
stone  begin  to  reappear ;  these  become  more  numerous  as 
we  descend ;  the  smaller  debris  also  appears,  and  finally, 
at  some  distance  below  the  fall,  the  moraine  is  completely 
restored,  and  begins  to  exercise  its  protecting  influence  ; 
it  rises  upon  its  ridge  of  ice,  and  dominates  as  before  over 
the  surface  of  the  glacier. 

The  ice  under  the  moraines  and  sand-cones  is  of  a 
different  appearance  from  that  of  the  surrounding  glacier, 
and  the  principles  we  have  laid  down  enable  us  to  explain 
the  difference.  The  sun's  rays,  striking  upon  the  unpro- 
tected surface  of  the  glacier,  enter  the  ice  to  a  considera- 
ble depth ;  and  the  consequence  is,  that  the  ice  near  the 


268  TRANSPARENCY  OF  ICE  UNDER  THE  MORAINES. 

surface  of  the  glacier  is  always  disintegrated,  being  cut  up 
with  minute  fissures  and  cavities,  filled  with  water  and 
air,  which,  for  reasons  already  assigned,  cause  the  glacier, 
when  it  is  clean,  to  appear  white  and  opaque.  The  ice 
under  the  moraines,  on  the  contrary,  is  usually  dark  and 
transparent ;  I  have  sometimes  seen  it  as  black  as  pitch, 
the  blackness  being  a  proof  of  its  great  transparency, 
which  prevents  the  reflection  of  light  from  its  interior. 

The  ice  under  the  moraines  cannot  be  assailed  in  its 
depths  by  the  solar  heat,  because  this  heat  becomes 
obscure  before  it  reaches  the  ice,  and  as  such  it  lacks 
the  power  of  penetrating  the  substance.  It  is  also  com- 
municated in  great  part  by  way  of  contact,  instead  of  by 
radiation.  A  thin  film  at  the  surface  of  the  moraine-ice 
engages  all  the  heat  that  acts  upon  it,  its  deeper  portions 
remaining  intact  and  transparent. 


AND  GLACIER.  269 


GLACIER    MOTION. 

PRELIMINARY. 
(9.) 

THOUGH  a  glacier  is  really  composed  of  two  portions, 
one  above  and  the  other  below  the  snow-line,  the  term  gla- 
cier is  usually  restricted  to  the  latter,  while  the  French 
term  nSve  is  applied  to  the  former.  It  is  manifest  that  the 
snow  which  falls  upon  the  glacier  proper  can  contribute 
nothing  to  its  growth  or  permanence ;  for  every  summer 
is  not  only  competent  to  abolish  the  accumulations  of  the 
foregoing  winter,  but  to  do  a  great  deal  more.  During 
each  summer  indeed  a  considerable  quantity  of  the  ice  be- 
low the  snow-line  is  reduced  to  water ;  so  that,  if  the  waste 
were  not  in  some  way  supplied,  it  is  manifest  that  in  a  few 
years  the  lower  portion  of  the  glacier  must  entirely  disap- 
pear. The  end  of  the  Mer  de  Glace,  for  example,  could 
never  year  after  year  thrust  itself  into  the  valley  of  Cha- 
mouni,  were  there  not  some  agency  by  which  its  manifest 
waste  is  made  good.  This  agency  is  the  motion  of  the 
glacier. 

To  those  unacquainted  with  the  fact  of  their  motion,  but 
who  have  stood  upon  these  vast  accumulations  of  ice,  and 
noticed  their  apparent  fixity  and  rigidity,  the  assertion 
that  a  glacier  moves  must  appear  in  the  highest  degree 
startling  and  incredible.  They  would  naturally  share  the 
doubts  of  a  certain  professor  of  Tubingen,  who,  after  a 
visit  to  the  glaciers  of  Switzerland,  went  home  and  wrote 
a  book  flatly  denying  the  possibility  of  their  motion.  But 
reflection  comes  to  the  aid  of  sense,  and  qualifies  first 
impressions.  We  ask  ourselves  how  is  the  permanence 
of  the  glacier  secured  ?  How  are  the  moraines  to  be  ac- 


270  HUGI'S  MEASUKEMENTS. 

counted  for?  Whence  come  the  blocks  which  we  often 
find  at  the  terminus  of  a  glacier,  and  which  we  know 
belong  to  distant  mountains  ?  The  necessity  of  motion  to 
produce  these  results  becomes  more  and  more  apparent, 
until  at  length  we  resort  to  actual  experiment.  We  take 
two  fixed  points  at  opposite  sides  of  the  glacier,  so  that 
a  block  of  stone  which  rests  upon  the  ice  may  be  in  the 
straight  line  which  unites  the  points  ;  and  we  soon  find 
that  the  block  quits  the  line,  and  is  borne  downwards  by 
the  glacier.  We  may  well  realize  the  interest  of  the  man 
who  first  engaged  in  this  experiment,  and  the  pleasure 
which  he  felt  on  finding  that  the  block  moved ;  for  even 
now,  after  hundreds  of  observations  on  the  motion  of 
glaciers  have  been  made,  the  actual  observance  of  this 
motion  for  the  first  time  is  always  accompanied  by  a  thrill 
of  delight.  Such  pleasure  the  direct  perception  of  natu- 
ral truth  always  imparts.  Like  Antaeus,  we  touch  our 
mother,  and  are  refreshed  by  the  contatt. 

The  fact  of  glacier-motion  has  been  known  for  an  in- 
definite time  to  the  inhabitants  of  the  mountains ;  but  the 
first  who  made  the  quantitative  observations  of  the  motion 
was  Hugi.  He  found  that  from  1827  to  1830  his  cabin 
upon  the  glacier  of  the  Aar  had  moved  100  metres,  or 
about  110  yards,  downwards ;  in  1836  it  had  moved  714 
metres ;  and  in  1841  M.  Agassiz  found  it  at  a  distance  of 
1428  metres  from  its  first  position.  This  is  equivalent 
in  round  numbers  to  an  average  velocity  of  100  metres 
a  year.  In  1840  M.  Agassiz  fixed  the  position  of  the 
rock  known  as  the  H6tel  des  Neufchatelois ;  arid  on  the 
5th  of  September,  1841,  he  found  that  it  had  moved  213 
feet  downward.  Between  this  date  and  September,  1842, 
the  rock  moved  273  feet,  thus  accomplishing  a  distance 
of  486  feet  in  two  years. 

But  much  uncertainty  prevailed  regarding  the  motion  of 
the  boulders,  for  they  sometimes  rolled  upon  the  glacier, 


AGASSIZ'S   MEASUREMENTS.  271 

and  hence  it  was  resolved  to  use  stakes  of  wood  driven  into 
the  ice.  In  the  month  of  July,  1841,  M.  Escher  de  la 
Linth  fixed  a  system  of  stakes,  every  two  of  which  were 
separated  from  each  other  by  a  distance  of  100  metres, 
across  the  great  Aletsch  glazier.  A  considerable  number 
of  other  stakes  were  fixed  along'  the  glacier,  the  longitu- 
dinal separation  being  also  100  metres.  On  the  8th  of 
July  the  stakes  stood  at  a  depth  of  about  three  feet  in 
the  ice.  On  the  16th  of  August  he  returned  to  the  glacier. 
Almost  all  the  stakes  had  fallen,  and  no  trace,  even  of  the 
holes  in  which  they  had  been  sunk,  remained.  M.  Agassiz 
was  equally  unsuccessful  on  the  glacier  of  the  Aar.  It 
must  therefore  be  borne  in  mind,  that,  previous  to  the 
introduction  of  the  facile  modes  of  measurement  which  we 
now  employ,  severe  labour  and  frequent  disappointment 
had  taught  observers  the  true  conditions  of  success. 

After  his  defeat  upon  the  Aletsch,  M.  Escher  joined 
MM.  Agassiz  and  Desor  on  the  Aar  glacier,  where,  between 
the  31st  of  August  and  the  5th  of  September,  they  fixed 
in  concert  the  positions  of  a  series  of  blocks  upon  the  ice, 
with  the  view  of  measuring  their  displacements  the  follow- 
ing year. 

Another  observation  of  great  importance  was  also  com- 
menced in  1841.  Warned  by  previous  failures,  M.  Agassiz 
had  iron  boring-rods  carried  up  the  glacier,  with  which  he 
pierced  the  ice  at  six  places  to  a  depth  of  ten  feet,  and 
at  each  place  drove  a  wooden  pile  into  the  ice.  These  six 
stations  were  in  the  same  straight  line  across  the  glacier ; 
three  of  them  standing  upon  the  Finsteraar  and  three  on 
the  Lauteraar  tributary.  About  this  time  also  M.  Agassiz 
conceived  the  idea  of  having  the  displacements  measured 
the  year  following  with  precise  instruments,  and  also  of 
having  constructed,  by  a  professional  engineer,  a  map  of 
the  entire  glacier,  on  which  all  its  visible  "  accidents  " 
should  be  drawn  according  to  scale.  This  excellent  work 
18 


272  PROF.  J.  D.  FORBES  INVITED. 

was  afterwards  executed  by  M.  Wild,  now  Professor  of 
Geodesy  and  Topography  in  the  Polytechnic  School  of 
Zurich,  and  it  is  published  as  a  separate  atlas  in  connex- 
ion with  M.  Agassiz's  "  Systeme  Glaciaire." 

M.  Agassiz  is  a  naturalist,  and  he  appears  to  have  de- 
voted but  little  attention  to  the  study  of  physics.  At  all 
events,  the  physical  portions  of  his  writings  appear  to  me 
to  be  very  often  defective.  It  was  probably  his  own  con- 
sciousness of  this  deficiency  that  led  him  to  invoke  the 
advice  of  Arago  and  others  previous  to  setting  out  upon  his 
excursions.  It  was  also  his  desire  "  to  see  a  philosopher  so 
justly  celebrated  occupy  himself  with  the  subject,"  which 
induced  him  to  invite  Prof.  J.  D.  Forbes  of  Edinburgh 
to  be  his  guest  upon  the  Aar  glacier  in  1841.  On  the  8th 
of  August  they  met  at  the  Grimsel  Hospice,  and  for  three 
weeks  afterwards  they  were  engaged  together  daily  upon 
the  ice,  sharing  at  night  the  shelter  of  the  same  rude  roof. 
It  is  in  reference  to  this  visit  that  Prof.  Forbes  writes 
thus  at  page  38  of  the  "Travels  in  the  Alps:"  —  "Far 
from  being  ready  to  admit,  as  my  sanguine  companions 
wished  me  to  do  in  1841,  that  the  theory  of  glaciers  was 
complete,  and  the  cause  of  their  motion  certain,  after  pa- 
tiently hearing  all  they  had  to  say  and  reserving  my  opin- 
ion, I  drew  the  conclusion  that  no  theory  which  I  had  then 
heard  of  could  account  for  the  few  facts  admitted  on  all 
hands."  In  1842  Prof.  Forbes  repaired,  as  early  as  the 
state  of  the  snow  permitted,  to  the  Mer  de  Glace ;  he  worked 
there,  in  the  first  instance,  for  a  week,  and  afterwards 
crossed  over  to  Courmayeur  to  witness  a  solar  eclipse. 
The  result  of  his  week's  observations  was  immediately 
communicated  to  Prof.  Jameson,  then  editor  of  the  "  Ed- 
inburgh New  Philosophical  Journal." 

In  that  letter  he  announces  the  fact,  but  gives  no  details 
of  the  measurement,  that  "  the  central  part  of  the  glacier 
moves  faster  than  the  edges  in  a  very  considerable  propor- 


CENTRE  MOVES   QUICKEST.  273 

tioii;  quite  contrary  to  the  opinion  generally  enter- 
tained." He  also  announced  at  the  same  time  the  con- 
tinuous hourly  advance  of  the  glacier.  This  letter  bears 
the  date,  "  Courmayeur,  Piedmont,  4th  July,"  but  it  was 
not  published  until  the  month  of  October  following. 

Meanwhile  M.  Agassiz,  in  company  with  M.  Wild,  re- 
turned to  complete  his  experiment  upon  the  glacier  of 
the  Aar.  On  the  20th  of  July,  1842,  the  displacements 
of  the  six  piles  which  he  had  planted  the  year  before  were 
determined  by  means  of  a  theodolite.  Of  the  three  upon 
the  Finsteraar  affluent,  that  nearest  the  side  had  moved 
160  feet,  the  next  225  feet,  while  that  nearest  to  the  cen- 
tre had  moved  269  feet.  Of  those  on  the  Lauteraar,  that 
nearest  the  side  had  moved  215  feet,  the  next  210  feet, 
and  that  nearest  the  centre  246  feet.  These  observations 
were  perfectly  conclusive  as  to  the  quicker  motion  of  the 
centre  :  they  embrace  a  year's  motion  ;  and  the  magni- 
tude of  the  displacements,  causing  errors  of  inches,  which 
might  seriously  affect  small  displacements,  to  vanish,  jus- 
tifies us  in  ranking  this  experiment  with  the  most  satisfac- 
tory of  the  kind  that  have  ever  been  made.  The  results 
were  communicated  to  Arago  in  a  letter  dated  from  the 
glacier  of  the  Aar,  on  the  1st  of  August,  1842  ;  they  were 
laid  before  the  Academy  of  Sciences  on  the  29th  of  Au- 
gust, 1842,  and  are  published  in  the  "  Comptes  Rendus  " 
of  the  same  date. 

The  facts,  then,  so  far  as  I  have  been  able  to  collect 
them,  are  as  follows.  M.  Agassiz  commenced  his  experi- 
ment about  ten  months  before  Professor  Forbes,  and  the 
results  of  his  measurements,  with  quantities  stated,  were 
communicated  to  the  French  Academy  about  two  months 
prior  to  the  publication  of  the  letter  of  Professor  Forbes 
in  the  "Edinburgh  Philosophical  Journal."  But  the  lat- 
ter communication,  announcing  in  general  terms  the  fact 
of  the  speedier  central  motion,  was  dated  from  Cour- 


274  STATE  OF  THE  QUESTION. 

mayeur  twenty-seven  days  before  the  date  of  M.  Agassiz's 
letter  from  the  glacier  of  the  Aar. 

The  speedier  motion  of  the  central  portion  of  a  glacier 
has  been  justly  regarded  as  one  of  cardinal  importance, 
and  no  other  observation  has  been  the  subject  of  such  fre- 
quent reference  ;  but  the  general  impression  in  England 
is,  that  M.  Agassiz  had  neither  part  nor  lot  in  the  establish- 
ment of  the  above  fact ;  and  in  no  English  work  with  which 
I  am  acquainted  can  I  find  any  reference  to  the  above 
measurements.  Relying  indeed  upon  such  sources  for  my 
information,  I  remained  ignorant  of  the  existence  of  the 
paper  in  the  "  Comptes  Rendus  "  until  my  attention  was 
directed  to  it  by  Professor  Wheatstone.  In  the  next  follow- 
ing chapters  I  shall  have  to  state  the  results  of  some  of 
my  own  measurements,  and  shall  afterwards  devote  a  little 
time  to  the  consideration  of  the  cause  of  glacier-motion. 
In  treating  a  question  on  which  so  much  has  been  writ- 
ten, it  is  of  course  impossible,  as  it  would  be  undesira- 
ble, to  avoid  subjecting  both  my  own  views  and  those  of 
others  to  a  critical  examination.  But  in  so  doing  I  hope 
that  no  expression  shall  escape  me  inconsistent  with  the 
courtesy  which  ought  to  be  habitual  among  philosophers, 
or  with  the  frank  recognition  of  the  just  claims  of  my 
predecessors. 


MY  FIRST  OBSERVATION.  275 


MOTION  OF  THE  MER  DE  GLACE. 
(10.) 

ON  Tuesday,  the  14th  of  July,  1857,  I  made  my  first 
observation  on  the  motion  of  the  Mer  de  Glace.  Accom- 
panied by  Mr.  Hirst  I  selected  on  the  steep  slope  of  the 
Glacier  des  Bois  a  straight  pinnacle  of  ice,  the  front  edge 
of  which  was  perfectly  vertical.  In  coincidence  with  this 
edge  I  fixed  the  vertical  fibre  of  the  theodolite,  and  per- 
mitted the  instrument  to  stand  for  three  hours.  On 
looking  through  it  at  the  end  of  this  interval,  the  cross 
hairs  were  found  projected  against  the  white  side  of  the 
pyramid ;  the  whole  mass  having  moved  several  inches 
downwards. 

The  instrument  here  mentioned,  which  had  long  been 
in  use  among  engineers  and  surveyors,  was  first  applied 
to  measure  glacier-motion  in  1842 ;  by  Prof.  Forbes  on 
the  Mer  de  Glace,  and  by  M.  Agassiz  on  the  glacier  of  the 
Aar.  The  portion  of  the  theodolite  made  use  of  is  easily 
understood.  The  instrument  is  furnished  with  a  telescope 
capable  of  turning  up  and  down  upon  a  pivot,  without  the 
slightest  deviation  right  or  left ;  and  also  capable  of  turn- 
ing right  or  left  without  the  slightest  deviation  up  or 
down.  Within  the  telescope  two  pieces  of  spider's  thread, 
so  fine  as  to  be  scarcely  visible  to  the  naked  eye,  are 
drawn  across  the  tube  and  across  each  other.  When  we 
look  through  the  telescope  we  see  these  fibres,  their  point 
of  intersection  being  exactly  in  the  centre  of  the  tube  ; 
and  the  instrument  is  furnished  with  screws  by  means  of 
which  this  point  can  be  fixed  upon  any  desired  object  with 
the  utmost  precision. 


276  MODE  OF  MEASUREMENT. 

In  setting  a  straight  row  of  stakes  across  the  glacier, 
our  mode  of  proceeding  was  in  all  cases  this.  The  the- 
odolite was  placed  on  the  mountain-side  flanking  the 
glacier,  quite  clear  of  the  ice  ;  and  having  determined 
the  direction  of  a  line  perpendicular  to  the  axis  of  the 
glacier,  a  well-defined  object  was  sought  at  the  opposite 
side  of  the  valley  as  close  as  possible  to  this  direction ; 
the  object  being,  in  some  cases,  the  sharp  edge  of  a  cliff ; 
in  others,  a  projecting  corner  of  rock ;  and,  in  others,  a 
well-defined  mark  on  the  face  of  the  rock.  This  object 
and  those  around  it  were  carefully  sketched,  so  that  on 
returning  to  the  place  it  could  be  instantly  recognized. 
On  commencing  a  line  the  point  of  intersection  of  the 
two  spider's  threads  within  the  telescope  was  first  fixed 
accurately  upon  the  point  thus  chosen,  and  an  assistant 
carrying  a  straight  baton  was  sent  upon  the  ice.  By  rough 
signalling  he  first  stood  near  the  place  where  the  first 
stake  was  to  be  driven  in  ;  and  the  object  end  of  the  tele- 
scope was  then  lowered  until  he  came  within  the  field  of 
view.  He  held  his  staff  upright  upon  the  ice,  and,  in 
obedience  to  signals,  moved  upwards  or  downwards  until 
the  point  of  intersection  of  the  spider's  threads  exactly 
hit  the  bottom  of  the  baton  ;  a  concerted  signal  was 
then  made,  the  ice  was  pierced  with  an  augur  to  a  depth 
of  about  sixteen  inches,  and  a  stake  about  two  feet  long 
was  firmly  driven  into  it.  The  assistant  then  advanced 
for  some  distance  across  the  glacier ;  the  end  of  the 
telescope  was  now  gently  raised  until  he  and  his  upright 
staff  again  appeared  in  the  field  of  view.  He  then  moved 
as  before  until  the  bottom  of  his  staff  was  struck  by  the 
point  of  intersection,  and  here  a  second  stake  was  fixed  in 
the  ice.  In  this  way  the  process  was  continued  until  the 
line  of  stakes  was  completed. 

Before  quitting  the  station,  a  plummet  was  suspended 
from  a  hook  directly  underneath  the  centre  of  the  theo- 


THE  FIRST  LINE.  277 

dolite,  and  the  place  where  the  point  touched  the  ground 
was  distinctly  marked.  To  measure  the  motion  of  the 
line  of  stakes,  we  returned  to  the  place  a  day  or  two  after- 
wards, and  by  means  of  the  plummet  were  able  to  make 
the  theodolite  occupy  the  exact  position  which  it  occupied 
when  the  line  was  set  out.  The  telescope  being  directed 
upon  the  point  at  the  opposite  side  of  the  valley,  and  grad- 
ually lowered,  it  was  found  that  no  single  stake  along  the 
line  preserved  its  first  position  :  they  had  all  shifted  down- 
wards. The  assistant  was  sent  to  the  first  stake  ;  the 
point  which  it  had  first  occupied  was  again  determined, 
and  its  present  distance  from  that  point  accurately  meas- 
ured. The  same  thing  was  done  in  the  case  of  each  stake, 
and  thus  the  displacement  of  the  whole  row  of  stakes  was 
ascertained.*  The  time  at  which  the  stake  was  fixed, 
and  at  which  its  displacement  was  measured,  being  care- 
fully noted,  a  simple  calculation  determined  the  daily  mo- 
tion of  the  stake. 

Thus,  on  the  17th  of  July,  1857,  we  set  out  our  first 
line  across  the  Mer  de  Glace,  at  some  distance  below  the 
Montanvert ;  on  the  day  following  we  measured  the  pro- 
gress of  the  stakes.  The  observed  displacements  are  set 
down  in  the  following  table  :  — 

FIRST  LINE.  —  DAILY  MOTION. 


No.  of  stake.  Inches. 

WEST  1      moved  12| 

2  "  16| 

3  "  22£ 

4  " 

5  "  24 


No.  of  stake.  Inches. 

6  moved 

7  "  26| 
8 

9  "  28| 

10          "  35£  EAST. 


*  Great  care  is  necessary  on  the  part  of  the  man  who  measures  the  displace- 
ments. The  staff  ought  to  be  placed  along  the  original  line,  and  the  assist- 
ant ought  to  walk  along  until  the  foot  of  a  perpendicular  from  the  stake  is  at- 
tained. When  several  days'  motion  is  to  be  measured,  this  precaution  is  ab- 
solutely necessary ;  the  eye  being  liable  to  be  grossly  deceived  in  guessing  the 
direction  of  a  perpendicular. 


278         THE   CENTRE-POINT  NOT   THE    QUICKEST. 

The  theodolite  in  this  case  stood  on  the  Montanvert  side 
of  the  valley,  and  the  stakes  are  numbered  from  this  side. 
We  see  that  the  motion  gradually  augments  from  the  1st 
stake  onward,  —  the  1st  stake  being  held  back  by  the 
friction  of  the  ice  against  the  flanking  mountain-side. 
The  stakes  4,  6,  and  8  have  no  motion  attached  to  them, 
as  an  accident  rendered  the  measurement  of  their  dis- 
placements uncertain.  But  one  remarkable  fact  is  exhib- 
ited by  this  line  ;  the  7th  stake  stood  upon  the  middle  of 
the  glacier,  and  we  see  that  its  motion  is  by  no  means 
the  quickest ;  it  is  exceeded  in  this  respect  by  the  stakes 
9  and  10. 

The  portion  of  the  glacier  on  which  the  10th  stake  stood 
was  very  much  cut  up  by  crevasses,  and,  while  the  assist- 
ant was  boring  it  with  his  auger,  the  ice  beneath  him  was 
observed,  through  the  telescope,  to  slide  suddenly  forward 
for  about  4  inches.  The  other  stakes  retained  their  po- 
sitions, so  that  the  movement  was  purely  local.  Deduct- 
ing the  4  inches  thus  irregularly  obtained,  we  should  have 
a  daily  motion  of  31  \  inches  for  stake  No.  10.  The  place 
was  watched  for  some  time,  but  the  slipping  was  not  re- 
peated ;  and  a  second  measurement  on  the  succeeding  day 
made  the  motion  of  the  10th  stake  32  inches,  whilst  that 
of  the  centre  of  the  glacier  was  only  27. 

Here,  then,  was  a  fact  which  needed  explanation ;  but, 
before  attempting  this,  I  resolved,  by  repeated  measure- 
ments in  the  same  locality,  to  place  the  existence  of  the 
fact  beyond  doubt.  We  therefore  ascended  to  a  point 
upon  the  old  and  now  motionless  moraine,  a  little  above 
the  Montanvert  Hotel ;  and  choosing,  as  before,  a  well- 
defined  object  at  the  opposite  side  of  the  valley,  we  set 
between  it  and  the  theodolite  a  row  of  twenty  stakes 
across  the  glacier.  Their  motions,  measured  on  a  sub- 
sequent day,  and  reduced  to  their  daily  rate,  gave  the  re- 
sults set  down  in  the  following  table :  — 


CORROBORATIVE  MEASUREMENTS. 


279 


SECOND  LINE. —  DAILY  MOTION. 


No.  of  stake. 

Inches. 

No.  of  stake.                    Inches. 

WEST   1 

moved 

74 

11         moved       21 

2 

u 

10| 

12             «              22| 

3 

tt 

124 

13 

21 

4 

d 

14 

14 

22^ 

5 

« 

16 

15 

OQl 

6 

u 

161 

16 

211 

7 

« 

172 

17 

224 

8 

" 

19 

18 

25| 

1     9 

u 

19£ 

19 

10 

fi 

21 

20             '            25|  EAST. 

As  regards  the  retardation  of  the  side,  we  observe  here 
the  same  fact  as  that  revealed  by  our  first  line,  —  the  mo- 
tion gradually  augments  from  the  first  stake  to  the  last. 
The  stake  No.  20  stood  upon  the  dirty  portion  of  the  ice, 
which  was  derived  from  the  Talefre  tributary  of  the  Mer 
de  Glace,  and  far  beyond  the  middle  of  the  glacier. 
These  measurements,  therefore,  corroborate  that  made 
lower  down,  as  regards  the  non-coincidence  of  the  point 
of  swiftest  motion  with  the  centre  of  the  glacier. 

But  it  will  be  observed  that  the  measurements  do  not 
show  any  retardation  of  the  ice  at  the  eastern  extremity 
of  the  line  of  stakes,  —  the  motion  goes  on  augmenting 
from  the  first  stake  to  the  last.  The  reason  of  this  is, 
that  in  neither  of  the  cases  recorded  were  we  able  to  get 
the  line  quite  across  the  glacier ;  the  crevasses  and  broken 
ice-ridges,  which  intercepted  the  vision,  compelled  us  to 
halt  before  we  came  sufficiently  close  to  the  eastern  side 
to  make  its  retardation  sensible.  But  on  the  20th  of  July 
my  friend  Hirst  sought  out  an  elevated  station  on  the 
Chapeau,  or  eastern  side  of  the  valley,  whence  he  could 
command  a  view  from  side  to  side  over  all  the  humps  and 
inequalities  of  the  ice,  the  fixed  point  at  the  opposite  side, 
upon  which  the  telescope  was  directed,  being  the  corner 
of  a  window  of  the  Montanvert  Hotel.  Along  this  line 


280      A  NEW  PECULIAEITY   OF  GLACIER  MOTION. 

were  placed  twelve  stakes,  the  daily  motions  of  which 
were  found  to  be  as  follows:  — 


No.  of  stake. 
EAST  1 
2 
3 
4 
5 
6 


THIRD  LINE.  —  DAILY  MOTION. 


moved 


nches. 

No.  of  stake.                  Inches. 

19|- 

7        moved        24^ 

22| 

8 

25 

28| 

9             ' 

25 

30^ 

10             • 

18 

33| 

11 

.  . 

28| 

12             * 

8^  "V! 

WEST. 


The  numbering  of  the  stakes  along  this  line  commenced 
from  the  Chapeau  side  of  the  glacier,  and  the  retardation 
of  that  side  is  now  manifest  enough  ;  the  motion  gradu- 
ally augmenting  from  19£  to  33^  inches.  But,  comparing 
the  velocity  of  the  two  extreme  stakes,  we  find  that  the 
retardation  of  stake  12  is  much  greater  than  that  of 
stake  1.  Stake  5,  moreover,  which  moved  with  the  maxi- 
mum velocity,  was  not  upon  the  centre  of  the  glacier,  but 
much  'nearer  to  the  eastern  than  to  the  western  side. 

It  was  thus  placed  beyond  doubt  that  the  point  of 
maximum  motion  of  the  Mer  de  Glace,  at  the  place  re- 
ferred to,  is  not  the  centre  of  the  glacier.  But,  to  make 
assurance  doubly  sure,  I  examined  the  comparative  motion 
along  three  other  lines,  and  found  in  all  the  same  unde- 
viating  result. 

This  result  is  not  only  unexpected,  but  is  quite  at  vari- 
ance with  the  opinions  hitherto  held  regarding  the  motion 
of  the  Mer  de  Glace.  The  reader  knows  that  the  trunk- 
stream  is  composed  of  three  great  tributaries,  from  the 
Ge*ant,  the  Le*chaud,  and  the  Tal£fre.  The  Glacier  du 
Ge*ant  fills  more  than  half  of  the  trunk-valley,  and  the 
junction  between  it  and  its  neighbours  is  plainly  marked 
by  the  dirt  upon  the  surface  of  the  latter.  In  fact  four 
medial  moraines  are  crowded  together  on  the  eastern  side 


LAW  OF  MOTION  SOUGHT.  281 

of  the  glacier,  and  before  reaching  the  Montanvert  they 
have  strewn  their  debris  quite  over  the  adjacent  ice. 
A  distinct  limit  is  thus  formed  between  the  clean  Glacier 
du  Ge*ant  and  the  other  dirty  tributaries  of  the  trunk- 
stream. 

Now  the  eastern  side  of  the  Mer  de  Glace  is  observed 
on  the  whole  to  be  much  more  fiercely  torn  than  the 
western  side,  and  this  excessive  crevassing  has  been  re- 
ferred to  the  swifter  motion  of  the  Glacier  du  Geant.  It 
has  been  thought  that,  like  a  powerful  river,  this  glacier 
drags  its  more  sluggish  neighbours  after  it,  and  thus  tears 
them  in  the  manner  observed.  But  the  measurement  of 
the  foregoing  three  lines  shows  that  this  cannot  be  the  true 
cause  of  the  crevassing.  In  each  case  the  stakes  which 
moved  quickest  lay  upon  the  dirty  portion  of  the  trunk- 
stream,  far  to  the  east  of  the  line  of  junction  of  the  Glacier 
du  Geant,  which  in  fact  moved  slowest  of  all. 

The  general  view  of  the  glacier,  and  of  the  shape  of  the 
valley  which  it  filled,  suggested  to  me  that  the  analogy 
with  a  river  might  perhaps  make  itself  good  beyond  the 
limits  hitherto  contemplated.  The  valley  was  not  straight, 
but  sinuous.  At  the  Montanvert  the  convex  side  of  the 
glacier  was  turned  eastward  ;  at  some  distance  higher  up, 
near  the  passages  called  Les  Fonts,  it  was  turned  west- 
ward ;  and  higher  up  again  it  was  turned  once  more, 
for  a  long  stretch,  eastward.  Thus  between  Tr^laporte 
and  the  Fonts  we  had  what  is  called  a  point  of  contrary 
flexure,  and  between  the  Fonts  and  the  Montanvert  a 
second  point  of  the  same  kind. 

Supposing  a  river,  instead  of  the  glacier,  to  sweep 
through  this  valley  ;  its  point  of  maximum  motion  would 
not  always  remain  central,  but  would  deviate  towards  that 
side  of  the  valley  to  which  the  river  turned  its  convex 
boundary.  Indeed  the  positions  of  towns  along  the  banks 
of  a  navigable  river  are  mainly  determined  by  this  circum- 


282      CONJECTURE  REGARDING  CHANGE  OF  FLEXURE. 

stance.  They  are,  in  most  cases,  situate  on  the  convex 
sides  of  the  bends,  where  the  rush  of  the  water  prevents 
silting  up.  Can  it  be  then  that  the  ice  exhibits  a  simi 
lar  deportment  ?  that  the  same  principle  which  regulates 
the  distribution  of  people  along  the  banks  of  the  Thames 
is  also  acting  with  silent  energy  amid  the  glaciers  of  the 
Alps  ?  If  this  be  the  case,  the  position  of  the  point  of 
maximum  motion  ought,  of  course,  to  shift  with  the 
bending  of  the  glacier.  Opposite  the  Fonts,  for  example, 
the  point  ought  to  be  on  the  Glacier  du  Geant,  and  west- 
ward of  the  centre  of  the  trunk-stream ;  while,  higher  up, 
we  ought  to  have  another  change  to  the  eastern  side,  in 
accordance  with  the  change  of  flexure. 

On  the  25th  of  July  a  line  was  set  out  across  the  glacier, 
one  of  its  fixed  termini  being  a  mark  upon  the  first  of  the 
three  Fonts.  The  motion  of  this  line,  measured  on  a  sub- 
sequent day,  and  reduced  to  its  daily  rate,  was  found  to 
be  as  follows  :  — 

FOURTH  LINE. —  DAILY  MOTION. 


No.  of  stake.                    Inches. 

No.  of  stake.                 Inches. 

EAST  1         moved          6^ 

10        moved        21 

2 

8 

11 

20^ 

3 

12* 

12 

234 

4 

154 

13 

234 

5 

15* 

14 

21 

6 

18| 

15 

224 

7 

184 

16 

174 

8 
9 

19i 

17 

15  WEST. 

This  line,  like  the  third,  was  set  out  and  numbered  from 
the  eastern  side  of  the  glacier,  the  theodolite  occupying 
a  position  on  the  heights  of  the  Echelets.  A  moment's 
inspection  of  the  table  reveals  a  fact  different  from  that 
observed  on  the  third  line ;  there  the  most  easterly  stake 
moved  with  more  than  twice  the  velocity  of  the  most 
westerly  one ;  here,  on  the  contrary,  the  most  westerly 


CONJECTURE   TESTED.  283 

stake  moves  with  more  than  twice  the  velocity  of  the 
most  easterly  one. 

To  enable  me  to  compare  the  motion  of  the  eastern  and 
western  halves  of  the  glacier  with  greater  strictness,  my 
able  and  laborious  companion  undertook  the  task  of  mea- 
suring with  a  surveyor's  chain  the  line  just  referred  to  ; 
noting  the  pickets  which  had  been  fixed  along  the  line, 
and  the  other  remarkable  objects  which  it  intersected. 
The  difficulty  of  thus  directing  a  chain  over  crevasses  and 
ridges  can  hardly  be  appreciated  except  by  those  who  have 
tried  it.  Nevertheless,  the  task  was  accomplished,  and  the 
width  of  the  Mer  de  Glace,  at  this  portion  of  its  course, 
was  found  to  be  863  yards,  or  almost  exactly  half  a  mile. 

Referring  to  the  last  table,  it  will  be  seen  that  the  two 
stakes  numbered  12  and  13  moved  with  a  common  velo- 
city of  23J  inches  per  day,  and  that  their  motion  is  swifter 
than  that  of  any  of  the  others.  The  point  of  swiftest  mo- 
tion may  be  taken  midway  between  them,  and  this  point 
was  found  by  measurement  to  lie  233  yards  west  of  the 
dirt  which  marked  the  junction  of  the  Glacier  du  Ge'ant 
with  its  fellow  tributaries  :  whereas,  in  the  former  cases, 
it  lay  a  considerable  distance  east  of  this  limit.  Its  dis- 
tance from  the  eastern  side  of  the  glacier  was  601  yards, 
and  from  the  western  side  262  yards,  being  1TO  yards 
west  of  the  centre  of  the  glacier. 

But  the  measurements  enabled  me  to  take  the  stakes  in 
pairs,  and  to  compare  the  velocity  of  a  number  of  them 
which  stood  at  certain  distances  from  the  eastern  side  of 
the  valley,  with  an  equal  number  which  stood  at  the  same 
distances  from  the  western  side.  By  thus  arranging  the 
points  two  by  two,  I  was  able  to  compare  the  motion  of 
the  entire  body  of  the  ice  at  the  one  side  of  the  central 
line  with  that  of  the  ice  at  the  other  side.  Stake  17  stood 
about  as  far  from  the  western  side  of  the  glacier  as 
stake  3  did  from  its  eastern  side  ;  16  occupied  the  same 
relation  to  4  ;  15  to  5 ;  13  to  7 ;  and  12  to  9. 


284 


WESTERN  HALF  MOVES    QUICKEST. 


Calling  each  pair  of  points  which  thus  stand  at  equal 
distances  from  the  opposite  sides  corresponding  points,  the 
following  little  table  exhibits  their  comparative  motions :  — 

NUMBERS  AND  VELOCITIES  OF  CORRESPONDING  POINTS   ON 
THE  FOURTH  LINE. 


No.  Vel. 

West   17  15 
East    3  12 


No.  Vel. 
16  17£ 
4  15| 


No.  Vel. 
15  22£ 
5  15 


No.  Vel. 

13  23| 

7  18 


No.  Vel. 

12  23£ 

9  19|- 


The  table  explains  itself.  We  see  that  while  stake  17, 
which  stands  west  of  the  centre,  moves  15  inches,  stake  3, 
which  stands  an  eqiial  distance  east  of  the  centre,  moves 
only  12|  inches.  Comparing  every  pair  of  the  other  points, 
we  find  the  same  to  hold  good ;  the  western  stake  moves 
in  each  case  faster  than  the  corresponding  eastern  one. 
Hence,  the  entire  western  half  of  the  Mer  de  Glace,  at  the 
place  crossed  by  our  fourth  line,  moves  more  quickly  than 
the  eastern  half  of  the  glacier. 

We  next  proceeded  farther  up,  and  tested  the  contrary 
curvature  of  the  glacier,  opposite  to  Trelaporte.  The 
station  chosen  for  this  purpose  was  on  a  grassy  platform 
of  the  promontory,  whence,  on  the  28th  of  July,  a  row  of 
stakes  was  fixed  at  right  angles  to  the  axis  of  the  glacier. 
Their  motions,  measured  on  the  31st,  gave  the  following 
results :  — 

FIFTH  LINE.*  —  DAILY  MOTION. 


No.  of  stake. 

Inches.                 |        No.  of  stake.                    Inches. 

WEST  1       moved 

m 

9       moved         19| 

2             " 

13£ 

10 

19 

3              " 

12| 

11 

VH 

4             « 

15 

12 

17* 

5             " 

is* 

13 

16 

6             " 

16 

14 

14| 

7            '« 

17i 

15            "            10  EAST. 

8 

191 

*  The  details  of  the  measurement  of  the  fourth  and  fifth  lines  are  pub- 
lished in  the  "Philosophical  Transactions,"  vol.  cxlix.  p.  261. 


EASTERN  HALF  MOVES  QUICKEST.  285 

This  line  was  set  out  and  numbered  from  the  Trelaporte 
side  of  the  valley,  and  was  also  measured  by  Mr.  Hirst, 
over  boulders,  ice-ridges,  chasms,  and  moraines.  The  en- 
tire width  of  the  glacier  here  was  found  to  be  893  yards, 
or  somewhat  wider  than  it  is  at  the  Fonts.  It  will  also 
be  observed  that  its  motion  is  somewhat  slower. 

An  inspection  of  the  notes  of  this  line  showed  me  that 
stakes  3  and  14,  4  and  12,  7  and  10,  were  "  correspond- 
ing points ; "  the  first  of  each  pair  standing  as  far  from 
the  western  side,  as  the  second  stood  from  the  eastern. 
In  the  following  table  these  points  and  their  velocities  are 
arranged  exactly  as  in  the  case  of  the  fourth  line. 

NUMBERS  AND  VELOCITIES  OF  THE  CORRESPONDING  POINTS 
ON  THE  FIFTH  LINE. 

No.    Vel.  No.    Vel.  No     Vel. 

West  3     12|  4     15  7     17£ 

East  14     14|  10     19 

In  each  case  we  find  that  the  stake  on  the  eastern  side 
moves  more  quickly  than  the  corresponding  one  upon  the 
western  side :  so  that  where  the  fifth  line  crosses  the  glacier 
the  eastern  half  of  the  Mer  de  Glace  moves  more  quickly 
than  the  western  half.  This  is  the  reverse  of  the  result  ob- 
tained at  our  fourth  line,  but  it  agrees  with  that  obtained 
on  our  first  three  lines,  where  the  curvature  of  the  valley 
is  similar.  The  analogy  between  a  river  and  a  glacier 
moving  through  a  sinuous  valley  is  therefore  complete. 

Supposing  the  points  of  maximum  motion  to  be  deter- 
mined for  a  great  number  of  lines  across  the  glacier,  the 
line  uniting  all  these  points  is  what  mathematicians  would 
call  the  locus  of  the  point  of  maximum  motion.  At  Trela- 
porte  this  line  would  lie  east  of  the  centre ;  at  the  Pouts 
it  would  lie  west  of  the  centre ;  hence,  in  passing  from 
Trelaporte  to  the  Ponts,  it  must  cross  the  axis  of  the 
glacier.  Again,  at  the  Montanvert,  it  would  lie  east  of  the 


286 


LOCUS  OF  POINT  OF  SWIFTEST  MOTION. 


centre,  and  between  the  Fonts  and  the  Montanvert  the 
axis  of  the  glacier  would  be  crossed  a  second  time.  Sup- 
posing the  dotted  line  in  Fig.  21  to  represent  the  middle 


N 


Fig.  21. 


line  of  the  glacier,  then  the  defined  line  would  represent 
the  locus  of  the  point  of  maximum  motion.  It  is  a  curve 
more  deeply  sinuous  than  the  valley  itself,  and  it  crosses 
the  axis  of  the  glacier  at  each  point  of  contrary  flexure. 

To  complete  our  knowledge  of  the  motion  of  the  Mer  de 
Glace,  we  afterwards  determined  the  velocity  of  its  two 
accessible  tributaries,— the  Glacier  du  Geant,  and  the  Gla- 
cier de  L^chaud.  On  the  29th  of  July,  a  line  of  stakes  was 
set  out  across  the  former,  a  little  above  the  Tacul,  and  their 
motion  was  subsequently  found  to  be  as  follows  :  — 


SIXTH  LINE.  —  DAILY  MOTION. 


No.  of  stake. 

2 
3 
4 
5 


moved 


Inches. 
11 
10 
12 
13 
12 


No.  of  stake.  Inches. 

6  moved  12| 
10* 
10 


7 

8 

9 

10 


The  width  of  the  glacier  at  this  place  we  found  to  be 
1134  yards,  and  its  maximum  velocity,  as  shown  by  the 
foregoing  table,  13  inches  a  day. 

On  the  1st  of  August  a  line  was  set  out  across  the 
Glacier  de  L^chaud,  above  its  junction  with  the  Talefre : 
it  commenced  beneath  the  block  of  stone  known  as  the 
Pierre  de  Be'ranger.  The  displacements  of  the  stakes, 
measured  upon  the  3rd  of  August,  gave  the  following 
results :  — 


SQUEEZING  AT   TR&LAPORTE.  287 

SEVENTH  LINE.  —  DAILY  MOTION. 


No.  of  stake.  Inches. 

1  moved         4£ 

2  "  84 

3  "  9£ 

4  "  9 

5  "  8 


No.  of  stake.  Inches. 

6  moved  7£ 

7  "  6£ 

8  "  81 


10 


The  width  of  the  Glacier  de  Le'chaud  at  this  place  was 
found  to  be  825  yards ;  its  maximum  motion,  as  shown 
by  the  table,  being  9£  inches  a-day.  This  is  the  slowest 
»ate  which  we  observed  upon  either  the  Mer  de  Glace  or 
its  tributaries.  The  width  of  the  Talefre  branch,  as  it 
descends  the  cascade,  or,  in  other  words,  before  it  is  in- 
fluenced by  the  pressure  of  the  Le'chaud,  was  found  ap- 
proximately to  be  638  yards. 

The  widths  of  the  tributaries  were  determined  for  the 
purpose  of  ascertaining  the  amount  of  lateral  compres- 
sion endured  by  the  ice  in  its  passage  through  the  neck 
of  the  valley  at  Trelaporte.  Adding  all  together  we 
have :  — 

Geant 1134  yards. 

Le'chaud 825     " 

Talefre 638    " 

Total       ....    2597  yards. 

These  three  branches,  as  shown  by  the  actual  measure- 
ment of  our  5th  line,  are  forced  at  Trelaporte  through  a 
channel  893  yards  wide  ;  the  width  of  the  trunk-stream 
is  a  little  better  than  one-third  of  that  of  its  tributaries, 
and  it  passes  through  this  gorge  at  a  velocity  of  nearly 
20  inches  a  day. 

Limiting  our  view  to  one  of  the  tributaries  only,  the 
result  is  still  more  impressive.  Previous  to  its  junction 
with  the  Talefre,  the  Glacier  de  Le'chaud  stretches  before 
the  observer  as  a  broad  river  of  ice,  measuring  825  yards 
across  :  at  Trelaporte  it  is  squeezed,  in  a  frozen  vice, 
between  the  Talefre  on  one  side  and  the  Ge*ant  on  the 
19 


288  THE  IJSCHAUD  A  DRIBLET. 

other,  to  a  driblet,  measuring  85  yards  in  width,  or  about 
one-tenth  of  its  former  transverse  dimension.  It  will  of 
course  be  understood  that  it  is  the  form  and  not  the 
volume  of  the  glacier  that  is  affected  to  this  enormous 
extent  by  the  pressure. 

Supposing  no  waste  took  place,  the  Glacier  de  Le'chaud 
would  force  precisely  the  same  amount  of  ice  through  the 
"  narrows  "  at  Trelaporte,  in  one  day,  as  it  sends  past  the 
Pierre  de  Be'ranger.  At  the  latter  place  its  velocity  is 
about  half  of  what  it  is  at  the  former,  but  its  width  i§ 
more  than  nine  times  as  great.  Hence,  if  no  waste  took 
place,  its  depth,  at  Trelaporte,  would  be  at  least  4|-  times 
its  depth  opposite  the  Pierre  de  Beranger.  Superficial 
and  sub-glacial  melting  greatly  modify  this  result.  Still 
I  think  it  extremely  probable  that  observations  directed 
to  this  end  would  prove  the  comparative  shallowness  of 
the  upper  portions  of  the  Glacier  de  Le'chaud. 


FIRST  ATTEMPT  AT  MEASUREMENT.  289 

ICE-WALL     AT     THE    TACUL. 

VELOCITIES    OF  TOP   AND   BOTTOM. 

(11.) 

As  regards  the  motion  of  the  surface  of  a  glacier,  two 
laws  are  to  be  borne  in  mind:  1st,  that  regarding  the 
quicker  movement  of  the  centre  ;  2nd,  that  regarding  the 
locus  of  the  point  of  maximum  motion.  Our  next  care 
must  be  to  compare  the  motion  of  the  surface  of  a  glacier 
with  the  motion  of  those  parts  which  lie  near  its  bed. 
Rendu  first  surmised  that  the  bottom  of  the  glacier  was 
retarded  by  friction,  and  both  Professor  Forbes*  and  M. 
Martinsf  have  confirmed  the  conjecture.  Theirs  are  the 
only  observations  which  we  possess  upon  the  subject ;  and 
I  was  particularly  desirous  to  instruct  myself  upon  this 
important  head  by  measurements  of  my  own. 

During  the  summer  of  185T  the  eastern  side  of  the 
Glacier  du  Geant,  near  the  Tacul,  exposed  a  nearly  ver- 
tical precipice  of  ice,  measuring  140  feet  from  top  to 
bottom.  I  requested  Mr.  Hirst  to  fix  two  stakes  in  the 
same  vertical  plane,  one  at  the  top  of  the  precipice  and 
one  near  the  bottom.  This  he  did  upon  the  3rd  of  August, 
and  on  the  5th  I  accompanied  him  to  measure  the  progress 
of  the  stakes.  On  the  summit  of  the  precipice,  and  run- 
ning along  it,  was  the  lateral  moraine  of  the  glacier.  The 
day  was  warm  and  the  ice  liquefying  rapidly,  so  that  the 
boulders  and  debris,  deprived  incessantly  of  their  support, 
came  in  frequent  leaps  and  rushes  down  the  precipice. 
Into  this  peril  my  guide  was  about  to  enter,  to  measure 

*  "  Edinb.  Phil.  Journ.,"  Oct.  1846,  p.  417. 
t  Agassiz,  "  Systeme  Glaciaire,"  p.  522. 


290      STAKES  FIXED  AT  TOP,  BOTTOM,  AND  CENTRE. 

the  displacement  of  the  lower  stake,  while  I  was  to  watch, 
and  call  out  the  direction  in  which  he  was  to  run  when  a 
stone  gave  way.  But  I  soon  found  that  the  initial  motion 
was  no  sure  index  of  the  final  motion.  By  striking  the 
precipice,  the  stones  were  often  deflected,  and  carried 
wide  of  their  original  direction.  I  therefore  stopped  the 
man,  and  sent  him  to  the  summit  of  the  precipice  to  re- 
move all  the  more  dangerous  blocks.  This  accomplished, 
he  descended,  and,  while  I  stood  beside  him,  executed  the 
required  measurement.  From  the  3rd  to  the  5th  of 
August  the  upper  stake  had  moved  twelve  inches,  and  the 
lower  one  six. 

Unfortunately  some  uncertainty  attached  itself  to  this 
result,  due  to  the  difficulty  of  fixing  the  lower  stake. 
The  guide's  attention  had  been  divided  between  his  work 
and  his  safety,  and  he  had  to  retreat  more  than  a  dozen 
times  from  the  falling  boulders  and  de'bris.  I,  on  the  other 
hand,  was  unwilling  to  accept  an  observation  of  such  im- 
portance with  a  shade  of  doubt  attached  to  it.  Hence  arose 
the  desire  to  measure  the  motion  myself.  On  the  llth  of 
August  I  therefore  reascended  to  the  Tacul,  and  fixed 
a  stake  at  the  top  of  the  precipice,  and  another  at  the  bot- 
tom. While  sitting  on  the  old  moraine  looking  at  the  two 
pickets,  the  importance  of  determining  the  motion  of  a 
point  midway  between  the  top  and  bottom  forcibly  oc- 
curred to  me,  but,  on  mentioning  it  to  my  guide,  he 
promptly  pronounced  any  attempt  of  the  kind  absurd. 

On  scanning  the  place  carefully,  however,  the  value  of 
the  observation  appeared  to  me  to  outweigh  the  amount 
of  danger.  I  therefore  took  my  axe,  placed  a  stake  and 
an  augur  against  my  breast,  buttoned  my  coat  upon  them, 
and  cut  an  oblique  staircase  up  the  wall  of  ice,  until  I 
reached  a  height  of  forty  feet  from  the  bottom.  Here  the 
position  of  the  stake  being  determined  by  Mr.  Hirst,  who 
was  at  the  theodolite,  I  pierced  the  ice  with  the  auger, 


THROUGH  GLOOM  TO  THE  TACUL.       291 

drove  in  the  stake,  and  descended  without  injury.  During 
the  whole  operation  however  my  guide  growled  audibly. 

On  the  following  morning  we  commenced  the  ascent 
of  Mont  Blanc,  a  narrative  of  which  is  given  in  Part  I. 
We  calculated  on  an  absence  of  three  days,  and  estimated 
that  the  stakes  which  had  just  been  fixed  would  be  ready 
for  measurement  on  our  return ;  but  we  did  not  reach 
Chamouni  until  the  afternoon  of  Friday,  the  14th.  Heavy 
clouds  settled,  during  our  descent,  upon  the  summits 
behind  us,  and  a  thunder-peal  from  the  Aiguilles  soon 
heralded  a  fall  of  rain,  which  continued  without  inter- 
mission till  the  afternoon  of  the  16th,  when  the  atmo- 
sphere cleared,  and  showed  the  mountains  clothed  to  their 
girdles  with  snow.  The  Montanvert  was  thickly  covered, 
and  on  our  way  to  it  we  met  the  servants  in  charge  of 
the  cattle,  which  had  been  driven  below  the  snow-line  to 
obtain  food. 

On  Monday  morning,  the  17th,  a  dense  fog  filled  the 
valley  of  the  Mer  de  Glace.  I  watched  it  anxiously.  The 
stakes  which  we  had  set  at  the  Tacul  had  been  often 
in  my  thoughts,  and  I  wished  to  make  some  effort  to 
save  the  labour  and  peril  incurred  in  setting  them 
from  being  lost.  I  therefore  set  out,  in  one  of  the  clear 
intervals,  accompanied  by  my  friend  and  Simond,  deter- 
mined to  measure  the  motion  of  the  stakes,  if  possible, 
or  to  fix  them  rapre  firmly,  if  they  still  stood.  As  we 
passed,  however,  from  P  Angle  to  the  glacier,  the  fog 
became  so  dense  and  blinding  that  we  halted.  At  my  re- 
quest Mr.  Hirst  returned  to  the  Montanvert ;  and  Simond, 
leaving  the  theodolite  in  the  shelter  of  a  rock,  accom- 
panied me  through  the  obscurity  to  the  Tacul.  We  found 
the  topmost  stake  still  stuck  by  its  point  in  the  ice ;  but 
the  two  others  had  disappeared,  and  we  afterwards  dis- 
covered their  fragments  in  a  snow-buttress,  which  reared 
itself  against  the  base  of  the  precipice.  They  had  been 


292  DESCENT  OF  BOULDERS. 

hit  by  the  falling  stones,  and  crushed  to  pieces.  Having 
thus  learned  the  worst,  we  descended  to  the  Montanvert 
amid  drenching  rain. 

On  the  morning  of  the  18th  there  was  no  cloud  to 
be  seen  anywhere,  and  the  sunlight  glistened  brightly  on 
the  surface  of  the  ice.  We  ascended  to  the  Tacul.  The 
spontaneous  falling  of  the  stones  appeared  more  frequent 
this  morning  than  I  had  ever  seen  it.  The  sun  shone 
with  unmitigated  power  upon  the  ice,  producing  copious 
liquefaction.  The  rustle  of  falling  debris  was  incessant, 
and  at  frequent  intervals  the  boulders  leaped  down  the 
precipice,  and  rattled  with  startling  energy  amid  the  rocks 
at  its  base.  I  sent  Simond  to  the  top  to  remove  the  looser 
stones  ;  he  soon  appeared,  and  urged  the  moraine-shingle 
in  showers  down  the  precipice,  upon  a  bevelled  slope  of 
which  some  blocks  long  continued  to  rest.  They  were 
out  of  the  reach  of  the  guide's  baton  and  he  sought  to 
dislodge  them  by  sending  other  stones  down  upon  them. 
Some  of  them  soon  gave  way,  drawing  a  train  of  smaller 
shingle  after  them  ;  others  required  to  be  hit  many  times 
before  they  yielded,  and  others  refused  to  be  dislodged 
at  all.  I  then  cut  my  way  up  the  precipice  in  the  man- 
ner already  described,  fixed  the  stake,  and  descended  as 
speedily  as  possible.  We  afterwards  fixed  the  bottom 
stake,  and  on  the  20th  the  displacements  of  all  three  were 
measured.*  The  spaces  passed  over  ^by  the  respective 
stakes  in  24  hours  were  found  to  be  as  follows  :  — 

Inches. 

Top  stake  .  .  .6.00 
Middle  stake  .  .  4.50 
Bottom  stake  .  .  .  2.56 

The  height  of  the  precipice  was  140.8  feet,  but  it  sloped 
off  at  its  upper  portion.  The  height  of  the  middle 

*  On  this  latter  occasion  my  guide  volunteered  to  cut  the  steps  for  me 
up  to  the  pickets  ;  and  I  permitted  him  to  do  so.  In  fact,  he  was  at  last  as 
anxious  as  myself  to  see  the  measurement  carried  out. 


MOTION  OF  STAKES.  298 

stake  above  the  ground  was  35  feet,  and  of  the  bottom 
one  4  feet.  It  is  therefore  proved  by  these  measurements 
that  the  bottom  of  the  ice-wall  at  the  Tacul  moves  with 
less  than  half  the  velocity  of  the  top  ;  while  the  displace- 
ment of  the  intermediate  stake  shows  how  the  velocity 
gradually  increases  from  the  bottom  upwards. 


294  HALF  OF  SUMMER  MOTION. 


WINTER  MOTION  OF  THE  MER  DE   GLACE. 

(12.) 

THE  winter  measurements  were  executed  in  the  man- 
ner already  described,  on  the  28th  and  29th  of  December, 
1859.  The  theodolite  was  placed  on  the  mountain's  side 
flanking  the  glacier,  and  a  well-defined  object  was  chosen 
at  the  opposite  side  of  the  valley,  so  that  a  straight  line 
between  this,  object  and  the  theodolite  was  approximately 
perpendicular  to  the  axis  of  the  glacier.  Fixing  the  tele- 
scope in  the  first  instance  with  its  cross  hairs  upon  the 
object,  its  end  was  lowered  until  it  struck  the  point  upon 
the  glacier  at  which  a  stake  was  to  be  fixed.  Thanks  to 
the  intelligence  of  my  assistants,  after  the  fixing  of  the 
first  stake  they  speedily  took  up  the  line  at  all  other  points, 
requiring  very  little  correction  to  make  their  positions  per- 
fectly accurate.  On  the  day  following  that  on  which  the 
stakes  were  driven  in,  the  theodolite  was  placed  in  the  same 
position,  and  the  distances  to  which  the  stakes  had  moved 
from  their  original  positions  were  accurately  determined. 
As  already  stated,  the  first  line  crossed  the  glacier  about 
80  yards  above  the  Montanvert  Hotel. 

LINE  No.  I.  —  WINTER   MOTION  IN  TWENTY-FOUR  HOURS. 

No.  of  stake.  Inches. 
WEST  1  74 

2  11 

3  13£    . 

4  13 

5  13| 

6  14| 

The  maximum  here  is  fifteen  and  three-quarters  inches  ; 
the  maximum  summer  motion  of  the  same  portion  of  the 


No.  of  stake. 

Inches. 

7 

15| 

8 

15| 

9 

12* 

10 

12 

11 

6£  EAST. 

THE   SAME  LAW  IN  SUMMER  AND  WINTER.       295 

glacier  is  about  thirty  inches.  These  measurements  also 
show  that  in  winter,  as  well  as  in  summer,  the  side  of  the 
glacier  opposite  to  the  Montanvert  moves  quicker  than 
that  adjacent  to  it.  The  stake  which  moved  with  the 
maximum  velocity  was  beyond  the  moraine  of  La  Noire. 
The  second  line  crossed  the  glacier  about  130  yards  be- 
low the  Montanvert. 

LINE  No.  II.  —  WINTER  MOTION  IN  TWENTY-FOUR  HOURS. 


No.  of  stake. 

Inches. 

No.  of  stake. 

Inches. 

1 

71 

6 

151 

2 

9£ 

7 

17* 

3 

131 

8 

16* 

4 

16 

9 

14* 

5 

16 

10 

14 

The  maximum  here  is  an  inch  and  three-quarters  greater 
than  that  of  line  No.  1.  The  summer  maximum  at  this 
portion  of  the  glacier  also  exceeds  that  of  the  part  inter- 
sected by  line  No.  1.  The  surface  of  the  glacier  between 
both  lines  is  in  a  state  of  tension  which  relieves  itself  by 
a  system  of  transverse  fissures,  and  thus  permits  of  the 
quicker  advance  of  the  forward  portion. 

My  desire,  in  making  these  measurements,  was,  in  the 
first  place,  to  raise  the  winter  observations  of  the  motion 
to  the  same  degree  of  accuracy  as  that  already  enjoyed  by 
the  summer  ones.  Auguste  Balmat  had  already  made  a 
series  of  winter  observations  on  the  Mer  de  Glace ;  but 
they  were  made  in  the  way  employed  before  tjie  intro- 
duction of  the  theodolite  by  Agassiz  and  Forbes,  and 
shared  the  unavoidable  roughness  of  such  a  mode  of  mea- 
surement. They  moreover  gave  us  no  information  as  to 
the  motion  of  the  different  parts  of  the  glacier  along  the 
same  transverse  line,  and  this,  for  reasons  which  will  ap- 
pear subsequently,  was  the  point  of  chief  interest  to  me. 


296  THE  GLACIER  SLIDES. 

CAUSE   OF    GLACIER-MOTION. 

DE   SAUSSURE'S  THEORY. 
(13.) 

PERHAPS  the  first  attempt  at  forming  a  glacier-theory  is 
that  of  Scheuchzer  in  1705.  He  supposed  the  motion  to 
be  caused  by  the  conversion  of  water  into  ice  within  the 
glacier ;  the  known  and  almost  irresistible  expansion 
which  takes  place  on  freezing,  furnishing  the  force  which 
pushed  the  glacier  downward.  This  idea  was  illustrated 
and  developed  with  so  much  skill  by  M.  de  Charpentier, 
that  his  name  has  been  associated  with  it ;  and  it  is  com- 
monly known  as  the  Theory  of  Charpentier,  or  the  Dilata- 
tion-Theory. M.  Agassiz  supported  this  theory  for  a  time, 
but  his  own  thermometric  experiments  show  us  that  the 
body  of  the  glacier  is  at  a  temperature  of  32°  Fahr. ;  that 
consequently  there  is  no  interior  magazine  of  cold  to 
freeze  the  water  with  which  the  glacier  is  supposed  to  be 
incessantly  saturated.  So  that  these  experiments  alone, 
if  no  other  grounds  existed,  would  prove  the  insufficiency 
of  the  theory  of  dilatation.  I  may  however  add,  that  the 
arguments  most  frequently  urged  against  this  theory  deal 
with  an  assumption,  which  I  do  not  think  its  author  ever 
intended  to  make. 

Another  early  surmise  was  that  of  Altmann  and  Griiner 
(1760),  both  of  whom  conjectured  that  the  glacier  slid 
along  its  bed.  This  theory  received  distinct  expression 
from  De  Saussure  in  1799 ;  and  has  since  been  associated 
with  the  name  of  that  great  alpine  traveller,  being  usually 
called  the  "Theory  of  Saussure,"  and  sometimes  the 
"  Sliding  Theory."  It  is  briefly  stated  in  these  words :  — 


STRAINED   INTERPRETATION.  297 

"  Almost  every  glacier  reposes  upon  an  inclined  bed, 
and  those  of  any  considerable  size  have  beneath  them, 
even  in  winter,  currents  of  water  which  flow  between  the 
ice  and  the  bed  which  supports  it.  It  may  therefore  be 
understood  that  these  frozen  masses,  drawn  down  the 
slope  on  which  they  repose,  disengaged  by  the  water  from 
all  adhesion  to  the  bottom,  sometimes  even  raised  by  this 
water,  must  glide  by  little  and  little,  and  descend,  follow- 
ing the  inclinations  of  the  valleys,  or  of  the  slopes  which 
they  cover.  It  is  this  slow  but  continual  sliding  of  the 
ice  on  its  inclined  base  which  carries  it  into  the  lower 
valleys."  * 

De  Saussure  devoted  but  little  time  to  the  subject  of 
glacier-motion  ;  and  the  absence  of  completeness  in  the 
statement  of  his  views,  arising  no  doubt  from  this  cause, 
has  given  subsequent  writers  occasion  to  affix  what  I  can- 
not help  thinking  a  strained  interpretation  to  the  sliding 
theory.  It  is  alleged  that  he  regarded  a  glacier  as  a  per- 
fectly rigid  body  ;  that  he. considered  it  to  be  "  a  mass  of 
ice  of  small  depth,  and  considerable  but  uniform  breadth, 
sliding  down  a  uniform  valley,  or  pouring  from  a  narrow 
valley  into  a  wider  one."  f  The  introduction  "  of  the 
smallest  flexibility  or  plasticity"  is  moreover  emphatically 
denied  to  him.  J 

It  is  by  no  means  probable  that  the  great  author  of  the 
"  Voyages"  would  have  subscribed  to  this  "  rigid  "  anno- 
tation. His  theory,  be  it  remembered,  is  to  some  extent 
true :  the  glacier  moves  over  its  bed  in  the  manner  sup- 
posed, and  the  rocks  of  Britain  bear  to  this  day  the  traces 
of  these  mighty  sliders.  De  Saussure  probably  contented 
himself  with  a  general  statement  of  what  he  believed  to 

*  "  Voyages,"  §  535. 
t  Forbes's  "  Occ.  Pap.,"  p.  100. 

|  "  I  adhere  to  the  definition  as  excluding  the  introduction  of  the  smallest 
flexibility  or  plasticity."  —  Occ.  Pap.,  p.  96. 


298         GLACIER  OF  MONT  DOLENT. 

be  the  substantial  cause  of  the  motion.  He  visited  the 
Jardin,  and  saw  the  tributaries  of  the  Mer  de  Glace  turn- 
.  ing  round  corners,  welding  themselves  together,  and  after- 
wards moving  through  a  sinuous  trunk-valley  ;  and  it  is 
scarcely  credible  that  in  the  presence  of  such  facts  he 
would  have  denied  all  flexibility  to  the  glacier. 
•  The  statement  that  he  regarded  a  glacier  to  be  a  mass 
of  ice  of  uniform  width,  is  moreover  plainly  inconsistent 
with  the  following  description  of  the  glacier  of  Mont  Do- 
lent  :  —  "Its  most  elevated  plateau  is  a  great  circus, 
surrounded  by  high  cliffs  of  granite,  of  pyramidal  forms ; 
thence  the  glacier  descends  through  a  gorge,  in  which  it 
is  narrowed ;  but  after  having  passed  the  gorge,  it  en- 
larges again,  spreading  out  like  a  fan.  Thus  it  has  on 
the  whole  the  form  of  a  sheaf  tied  in  the  middle  and 
dilated  at  its  two  extremities."  * 

Curiously  enough,  this  very  glacier,  and  these  very 
words,  are  selected  by  M.  Rendu  as  illustrative  of  the 
plasticity  of  glaciers.  "  Nothing,"  he  says,  "shows  better 
the  extent  to  which  a  glacier  moulds  itself  to  its  locality, 
than  the  form  of  the  glacier  of  Mont  Dolent  in  the  Valley 
of  Ferret ;  "  and  he  adds,  in  connexion  with  the  same 
passage,  these  remarkable  words: — "There  is  a  multi- 
tude of  facts  which  would  seem  to  necessitate  the  belief 
that  the  substance  of  glaciers  enjoys  a  kind  of  ductility 
which  permits  it  to  mould  itself  to  the  locality  which  it 
occupies,  to  grow  thin,  to  swell,  and  to  narrow  itself  like 
a  soft  paste."  f 

*  "  Voyages,"  tome  ii.  p.  290. 

.  t  In  connexion  with  this  brief  sketch  of  the  "  Sliding  Theory,"  it  ought 
to  be  stated,  that  Mr.  Hopkins  has  proved  experimentally,  that  ice  may 
descend  an  incline  at  a  sensibly  uniform  rate,  and  that  the  velocity  is  aug- 
mented by  increasing  the  weight.  In  this  remarkable  experiment,  the  mo- 
tion was  due  to  the  slow  disintegration  of  the  lower  surface  of  the  ice.  See 
"Phil.  Mag.,"  1845,  vol.  26. 


RENDU'S  CHARACTER.  299 

RENDU'S  THEORY. 
(14.) 

M.  RENDU,  Bishop  of  Annecy,  to  whose  writings  I -have 
just  referred,  died  last  autumn.  He  was  a  man  of  great 
repute  in  his  diocese,  and  we  owe  to  him  one  of  the  most 
remarkable  essays  upon  glaciers  that  have  ever  appeared. 
His  knowledge  was  extensive,  his  reasoning  close  and 
accurate,  and  his  faculty  of  observation  extraordinary. 
With  these  were  associated  that  intuitive  power,  that  pre- 
sentiment concerning  things  as  yet  untouched  by  experi- 
ment, which  belong  only  to  the  higher  class  of  minds. 
Throughout  his  essay  a  constant  effort  after  quantitative 
accuracy  reveals  itself.  He  collects  observations,  makes 
experiments,  and  tries  to  obtain  numerical  results  ;  always 
taking  care,  however,  so  to  state  his  premises  and  qualify 
his  conclusions  that  nobody  shall  be  led  to  ascribe  to  his 
numbers  a  greater  accuracy  than  they  merit.  It  is  im- 
possible to  read  his  work,  and  not  feel  that  he  was  a  man 
of  essentially  truthful  mind,  and  that  science  missed  an 
ornament  when  he  was  appropriated  by  the  Church. 

The  essay  above  referred  to  is  printed  in  the  tenth  vol- 
ume of  the  Memoirs  of  the  Royal  Academy  of  Sciences 
of  Savoy,  published  in  1841,  and  is  entitled,  "  T/ieorie 
des  Glaciers  de  la  Savoie,  par  M.  le  Chanoine  Rendu, 
Chevalier  du  Merite  Civil  et  Secretaire  perpetuel"  The 
paper  had  been  written  for  nearly  two  years,  and  might 
have  remained  unprinted,  had  not  another  publication  on 
the  same  subject  called  it  forth. 

I  will  place  a  few  of.  the  leading  points  of  this  remark- 
able production  before  the  reader  ;  commencing  with  a 
generalization  which  is  highly  suggestive  of  the  character 
of  the  author's  mind. 


300      "THEORIE  DES   GLACIERS  DE  LA  SAVOIE." 

He  reflects  on  the  accumulation  of  the  mountain-snows, 
each  year  adding  fifty-eight  inches  of  ice  to  a  glacier.  This 
would  make  Mont  Blanc  four  hundred  feet  higher  in  a  cen- 
tury, and  four  thousand  feet  higher  in  a  thousand  years. 
"  It  is  evident,"  he  says,  "  that  nothing  like  this  occurs  in 
nature."  The  escape  of  the  ice  then  leads  him  to  make 
some  general  remarks  on  what  he  calls  the  "  law  of  circu- 
lation." "  The  conserving  will  of  the  Creator  has  em- 
ployed for  the  permanence  of  His  work  the  great  law  of 
circulation,  which,  strictly  examined,  is  found  to  repro- 
duce itself  in  all  parts  of  nature.  The  waters  circulate 
from  the  ocean  to  the  air,  from  the  air  to  the  earth,  and 
from  the  earth  to  the  ocean.  .  .  .  The  elements  of  organic 
substances  circulate,  passing  from  the  solid  to  the  liquid 
or  aeriform  condition,  and  thence  again  to  the  state  of 
solidity  or  of  organisation.  That  universal  agent  which 
we  designate  by  the  names  of  fire,  light,  electricity,  and 
magnetism,  has  probably  also  a  circulation  as  wide  as  the 
universe."  The  italics  here  are  Rendu's  own.  This  was 
published  in  1841,  but  written,  we  are  informed,  nearly 
two  years  before.  In  1842  Mr.  Grove  wrote  thus :  — 
"  Light,  heat,  magnetism,  motion,  and  chemical  affinity 
are  all  convertible  material  affections."  More  recently 
Helmholtz,  speaking  of  the  "  circuit "  formed  by  "  heat, 
light,  electricity,  magnetism,  and  chemical  affinity,"  writes 
thus  :  —  "  Starting  from  each  of  these  different  manifesta- 
tions of  natural  forces,  we  can  set  every  other  in  action." 
I  quote  these  passages  because  they  refer  to  the  same 
agents  as  those  named  by  M.  Rendu,  and  to  which  he 
ascribes  "  circulation"  Can  it- be  doubted  that  this  Sa- 
voyard priest  had  a  premonition  of  the  Conservation  of 
Force  ?  I  do  not  want  to  lay  more  stress  than  it  deserves 
upon  a  conjecture  of  this  kind  ;  but  its  harmony  with  an 
essay  remarkable  for  its  originality  gives  it  a  significance 
which,  if  isolated,  it  might  not  possess. 


GLACIERS   RIGHTLY  DIVIDED.  301 

With  regard  to  the  glaciers,  Rendu  commences  by  divid- 
ing them  into  two  kinds,  or  rather  the  self-same  glacier  into 
two  parts,  one  of  which  he  calls  the  "glacier  reservoir" 
the  other  the  "glacier  d'ecoulement"  —  two  terms  highly 
suggestive  of  the  physical  relationship  of  the  n6ve  and 
the  glacier  proper.  He  feeds  the  reservoirs  from  three 
sources,  the  principal  one  of  which  is  the  snow,  to  which 
he  adds  the  rain,  and  the  vapours  which  are  condensed 
upon  the  heights  without  passing  into  the  state  of  either 
rain  or  snow.  The  conversion  of  the  snow  into  ice  he 
supposes  to  be  effected  by  four  different  causes,  the  most 
efficacious  of  which  is  pressure*  It  is  needless  to  remark 
that  this  quite  agrees  with  the  views  now  generally  enter- 
tained. 

In  page  60  of  the  volume  referred  to  there  is  a  passage 
which  shows  that  the  "  veined  structure  "  of  the  glacier 
had  not  escaped  him,  though  it  would  seem  that  he  as- 
cribed it  to  stratification.  "  When,"  he  writes,  "  we  per- 
ceive the  profile  of  a  glacier  on  the  walls  of  a  crevasse,  we 
see  different  layers  distinct  in  colour,  but  more  particular- 
ly in  density ;  some  seem  to  have  the  hardness,  as  they 
have  the  greenish  colour,  of  glass ;  others  preserve  the 
whiteness  and  porosity  of  the  snow."  There  is  also  a  very 
close  resemblance  between  his  views  of  the  influence  of 
"  time  and  cohesion  "  and  those  of  Prof.  Forbes.  "  We  may 
conclude,"  he  writes,  "  that  time,  favouring  the  action  of 
affinity,  and  the  pressure  of  the  layers  one  upon  the  other, 
causes  the  little  crystals  of  which  snow  is  composed  to 
approach  each  other,  bring  them  into  contact,  and  con- 
vert them  into  ice."  f  Regelation  also  appears  to  have 
attracted  his  notice.  :£  "  When  we  fill  an  ice-house,"  he 
writes,  "  we  break  the  ice  into  very  small  fragments ; 
afterwards  we  wet  it  with  water  8  or  10  degrees  above  zero 
(Cent.)  in  temperature ;  but,  notwithstanding  this,  the 

*  "  Memoir/'  p.  77.  t  P.  75.  t  P.  71. 


302  OBSERVATIONS  AND   HYPOTHESES. 

whole  is  converted  into  a  compact  mass  of  ice."  He 
moreover  maintains,  in  almost  the  same  language  as  Prof. 
Forbes,*  the  opinion,  that  ice  has  always  an  inner  tempe- 
rature lower  than  zero  (Cent.).  He  believed  this  to  be  a 
property  "  inherent  to  ice."  "  Never,"  he  says,  "  can  a 
calorific  ray  pass  the  first  surface  of  ice  to  raise  the  tem- 
perature of  the  interior."  f 

He  notices  the  direction  of  the  glacier  as  influencing 
the  wasting  of  its  ridges  by  the  sun's  heat ;  ascribing  to  it 
the  effect  to  which  I  have  referred  in  explaining  the  wave- 
like  forms  upon  the  surface  of  the  Mer  de  Glace.  His 
explanation  of  the  Moulins,  too,  though  insufficient,  assigns 
a  true  cause,  and  is  an  excellent  specimen  of  physical 
reasoning. 

With  regard  to  the  diminution  of  the  glaciers  reservoirs, 
or,  in  other  words,  to  the  manner  in  which  the  ice  dis- 
appears, notwithstanding  the  continual  additions  made 
to  it,  we  have  the  following  remarkable  passage :  —  "In 
seeking  the  cause  of  the  diminution  of  glaciers,  it  has  oc- 
curred to  my  mind  that  the  ice,  notwithstanding  its  hard- 
ness and  its  rigidity,  can  only  support  a  given  pressure 
without  breaking  or  being  squeezed  out.  According  to  this 
supposition,  whenever  the  pressure  exceeds  that  force,  there 
will  be  rupture  of  the  ice,  and  a  flow  in  consequence.  Let 
us  take,  at  the  summit  of  Mont  Blanc,  a  column  of  ice 
reposing  on  a  horizontal  base.  The  ice  which  forms  the 
first  layer  of  that  column  is  compressed  by  the  weight  of 
all  the  layers  above  it ;  but  if  the  solidity  of  the  said  first 
layer  can  only  support  a  weight  equal  to  100,  when  the 
weight  exceeds  this  amount  there  will  be  rupture  and 
spreading  out  of  the  ice  of  the  base.  Now,  something  very 
similar  occurs  in  the  immense  crust  of  ice  which  covers  the 
summits  of  Mont  Blanc.  This  crust  appears  to  augment  at 
the  upper  surface  and  to  diminish  by  the  sides.  To  assure 

*  "  Philosophical  Magazine,"  1859.  t  "  Memoir,"  p.  69. 


MEASUREMENT    OF  MOTION.  303 

oneself  that  the  movement  is  due  to  the  force  of  pressure, 
it  would  be  necessary  to  make  a  series  of  experiments 
upon  the  solidity  of  ice,  such  as  have  not  yet  been  at- 
tempted." *  I  may  remark  that  such  experiments  sub- 
stantially verify  M.  Rendu's  notion. 

But  it  is  his  observations  and  reasoning  upon  the  gla- 
ciers cFecoulement  that  chiefly  interest  us.  The  passages 
in  his  writings  where  he  insists  upon  the  power  of  the 
glaciers  to  mould  themselves  to  their  localities,  and  com- 
pares them  to  a  soft  paste,  to  lava  at  once  ductile  and 
liquid,  are  well  known  from  the  frequent  and  flattering 
references  of  Professor  Forbes  ;  but  there  are  others  of 
much  greater  importance,  which  have  hitherto  remained 
unknown  in  this  country.  Regarding  the  motion  of  the 
Mer  de  Glace,  Rendu  writes  as  follows  :  — 

"  I  sought  to  appreciate  the  quantity  of  its  motion  ; 
but  I  could  only  collect  rather  vague  data.  I  questioned 
my  guides  regarding  the  position  of  an  enormous  rock  at 
the  edge  of  the  glacier,  but  still  upon  the  ice,  and  conse- 
quently partaking  of  its  motion.  The  guides  showed  me 
the  place  where  it  stood  the  preceding  year,  and  where 
it  had  stood  two,  three,  four,  and  five  years  previously ; 
they  showed  me  the  place  where  it  would  be  found  in  a 
year,  in  two  years,  &c. ;  so  certain  are  they  of  the  regu- 
larity of  the  motion.  Their  reports,  however,  did  not 
always  agree  precisely  with  each  other,  and  their  indica- 
tions of  time  and  distance  lack,  the  precision  without 
which  we  proceed  obscurely  in  the  physical  sciences.  In 
reducing  these  different  indications  to  a  mean,  I  found 
the  total  advance  of  the  glacier  to  be  about  40  feet  a  year. 
During  my  last  journey  I  obtained  more  certain  data, 
which  I  have  stated  in  the  preceding  chapter.  The  enor- 
mous difference  between  both  results  arises  from  the  fact 
that  the  latter  observations  were  made  at  the  centre  of  the 

*  Page  80. 

20 


304         THE  SIDES   OF  THE   GLACIER   RETARDED. 

glacier,  WHICH  MOVES  MORE  RAPIDLY,  while  the  former 
were  made  at  the  side,  where  the  ice  is  RETAINED  BY  THE 

FRICTION   AGAINST   ITS   ROCKY  WALLS."  * 

An  opinion,  founded  on  a  grave  misapprehension  which 
Rendu  enables  us  to  correct,  is  now  prevalent  in  this 
country,  not  only  among  the  general  public,  but  also 
among  those  of  the  first  rank  in  science.  The  nature  of 
the  mistake  will  be  immediately  apparent.  At  page  128 
of  the  "  Travels  in  the  Alps "  its  distinguished  author 
gives  a  sketch  of  the  state  of  our  knowledge  of  glacier- 
motion  previous  to  the  commencement  of  his  inquiries. 
He  cites  Ebel,  Hugi,  Agassiz,  Bakewell,  De  la  Beche, 
Shirwell,  Rendu,  and  places  them  in  open  contradiction 
to  each  other.  Rendu,  he  says,  gives  the  motion  of  the 
Mer  de  Glace  to  be  "  242  feet  per  annum ;  442  feet  per 
annum  ;  a  foot  a  day ;  400  feet  per  annum,  and  40  feet 
per  annum,  or  one-tenth  of  the  last !"....  and  he  adds, 
"  I  was  not  therefore  wrong  in  supposing  that  the  actual 
progress  of  a  glacier  was  yet  a  new  problem  when  I  com- 
menced my  observations  on  the  Mer  de  Glace  in  1842."  f 

In  the  "  North  British  Review  "  for  August,  1859,  a 
writer  equally  celebrated  for  the  brilliancy  of  his  discov- 
eries and  the  vigour  of  his  pen  collected  the  data  fur- 
nished by  the  above  paragraph  into  a  table,  which  he 
introduced  to  his  readers  in  the  following  words : — "It 
is  to  Professor  Forbes  alone  that  we  owe  the  first  and 
most  correct  researches  respecting  the  motion  of  glaciers ; 
and  in  proof  of  this,  we  have  only  to  give  the  following 
list  of  observations  which  had  been  previously  made. 

*  Page  95. 

t  At  page  38  of  the  "  Travels  "  the  following  passage  also  occurs  :  —  "I 
believe  that  I  may  safely  affirm  that  not  one  observation  of  the  rate  of 
motion  of  a  glacier,  either  ou  the  average  or  at  any  particular  season  of  the 
year,  existed  when  I  commenced  my  experiments  in  1 842." 


Name  of  glacier. 
Chamouni 

Annual  rate  of  motion. 
14  feet. 

Grindelwald 

25     « 

Aar 

240     «' 

Aar 

200     « 

Mer  de  Glace 

540     4' 

Mer  de  Glace 

600     " 

Mer  de  Glace 

300     " 

Mer  de  Glace 

365     " 

DISCREPANCIES  EXPLAINED.  305 

Observers. 
Ebel 
Ebel 
Hugi 
Agassiz 
Bakewell 
De  la  Beche 
Shirwell 
M.  Rendu 
Saussure's  Ladder  Mer  de  Glace  375    " 

.  .  .  Such  was  the  state  of  our  knowledge  when  Professor 
Forbes  undertook  the  investigation  of  the  subject." 

I  am  persuaded  that  the  writer  of  this  article  will  be 
the  first  to  applaud  any  attempt  to  remove  an  error 
which,  advanced  on  his  great  authority,  must  necessarily 
be  widely  disseminated.  The  numbers  in  the  above  table 
certainly  differ  widely,  and  it  is  perhaps  natural  to  con- 
clude that  such  discordant  results  can  be  of  no  value  ; 
but  the  fact  really  is  that  every  one  of  them  may  be  per- 
fectly correct.  This  fact,  though  overlooked  by  Professor 
Forbes,  was  clearly  seen  by  Rendu,  who  pointed  out  with 
perfect  distinctness  the  sources  from  which  the  discrepan- 
cies were  derived. 

"  It  is  easy,"  he  says,  "  to  comprehend  that  it  is  impos- 
sible to  obtain  a  general  measure,  —  that  there  ought  to  be 
one  for  each  particular  glacier.  The  nature  of  the  slope, 
the  number  of  changes  to  which  it  is  subjected,  the  depth 
of  the  ice,  the  widtli  of  the  couloir,  the  form  of  its  sides, 
and  a  thousand  other  circumstances,  must  produce  varia- 
tions in  the  velocity  of  the  glacier,  and  these  circumstances 
cannot  be  everywhere  absolutely  the  same.  Much  more, 
it  is  not  easy  to  obtain  this  velocity  for  a  single  glacier, 
and  for  this  reason.  In  those  portions  where  the  inclina- 
tion is  steep,  the  layer  of  ice  is  thin,  and  its  velocity  is 
great ;  in  those  where  the  slope  is  almost  nothing,  the  gla- 
cier swells  and  accumulates ;  the  mass  in  motion  being 
double,  triple,  &c.,the  motion  is  only  the  half,  the  third,  &c. 


306          LIQUID  MOTION  ASCRIBED  TO  GLACIER. 

u  But  this  is  not  all,"  adds  M.  Rendu.  "  Between  the 
Mer  de  Glace  and  a  river,  there  is  a  resemblance  so  com- 
plete that  it  is  impossible  to  find  in  the  latter  a  circumstance 
which  does  not  exist  in  the  former.  In  currents  of  water 
the  motion  is  not  uniform,  neither  throughout  their  width 
nor  throughout  their  depth ;  the  friction  of  the  bottom, 
that  of  the  sides,  the  action  of  obstacles,  cause  the  motion 
to  vary,  and  only  towards  the  middle  of  the  surface  is  this 
entire  ...."* 

In  1845  Professor  Forbes  appears  to  have  come  to  the 
same  conclusion  as  M.  Rendu ;  for  after  it  had  been 
proved  that  the  centre  of  the  Aar  glacier  moved  quicker 
than  the  side  in  the  ratio  of  fourteen  to  one,  he  accepted 
the  result  in  these  words :  "  The  movement  of  the  centre 
of  the  glacier  is  to  that  of  a  point  five  metres  from  the 
edge  as  FOURTEEN  to  ONE  :  such  is  the  effect  of  plastici- 
ty !  "  f  Indeed,  if  the  differences  exhibited  in  the  table 
were  a  proof  of  error,  the  observations  of  Professor  Forbes 
himself  would  fare  very  ill.  The  measurements  of  glacier- 
motion  made  with  his  own  hands  vary  from  less  than  42 
feet  a  year  to  848  feet  a  year,  the  mimimum  being  less 
than  one-twentieth  of  the  maximum ;  and  if  we  include 
the  observations  made  by  Balrnat,  the  fidelity  of  which 
has  been  certified  by  Professor  Forbes,  the  minimum  is 
only  one-thirty-seventh  of  the  maximum. 

There  is  another  point  connected  with  Rendu's  theory 
which  needs  clearing  up.  "  The  idea,"  writes  the  emi- 
nent reviewer,  "  that  a  glacier  is  a  semifluid  body  is  no 
doubt  startling,  especially  to  those  who  have  seen  the 
apparently  rigid  ice  of  which  it  is  composed.  M.  Rendu 
himself  shrank  from  the  idea,  and  did  not  scruple  to  say 
that '  the  rigidity  of  a  mass  of  ice  was  in  direct  opposition  to 
it ; '  and  we  think  that  Professor  Forbes  himself  must  have 
stood  aghast  when  his  fancy  first  associated  the  notion  of 

*  "  The'orie,"  p.  96.  t  "  Occ.  Pap.,"  p.  74. 


NORTH  BRITISH  REVIEW.  307 

imperfect  fluidity  with  the  solid  or  even  the  fissured  ice  of 
the  glacier,  and  when  he  saw  in  his  mind's  eye  the  glaciers 
of  the  Alps  flowing  like  a  river  along  their  rugged  bed. 
A  truth  like  this  was  above  the  comprehension  and  beyond 
the  sympathy  of  the  age  ;  and  it  required  a  moral  power  of 
no  common  intensity  to  submit  it  to  the  ordeal  of  a  shallow 
philosophy,  and  the  sneers  of  a  presumptuous  criticism." 

These  are  strong  words ;  but  the  fact  is  that,  so  far 
from  "  shrinking  "  from  the  idea,  Rendu  affirmed,  with  a 
clearness  and  an  emphasis  which  have  not  been  ex- 
ceeded since,  that  all  the  phenomena  of  a  river  were 
reproduced  upon  the  Mer  de  Glace  ;  its  deeps,  its  shal- 
lows, its  widenings,  its  narrowings,  its  rapids,  its  places 
of  slow  motion,  and  the  quicker  flow  of  its  centre  than 
of  its  sides.  He  did  not  shrink  from  accepting  a  differ- 
ence between  the  central  and  lateral  motion  amounting  to 
a  ratio  of  ten  to  one,  —  a  ratio  so  large  that  Professor  Forbes 
at  one  time  regarded  the  acceptance  of  it  as  a  simple 
absurdity.  In  this  he  was  perhaps  justified  ;  for  his  own 
first  observations,  which,  however  valuable,  were  hasty  and 
incomplete,  gave, him  a  maximum  ratio  of  about  one  and 
a  half  to  one,  while  the  ratio  in  some  cases  was  nearly  one 
of  equality.  The  observations  of  Agassiz  however  show 
that  the  ratio,  instead  of  being  ten  to  one,  may  be  infinity 
to  one  ;  for  the  lateral  ice  may  be  so  held  back  by  a  local 
obstacle  that  in  the  course  of  a  year  it  shall  make  no  sen- 
sible advance  at  all. 

From  one  thing  only  did  M.  Rendu  shrink  ;  and  it  is  the 
thing  regarding  which  we  are  still  disunited.  He  shrank 
from  stating  the  physical  quality  of  the  ice  in  virtue  of 
which  a  glacier  moved  like  a  river.  He  demands  experi- 
ments upon  snow  and  ice  to  elucidate  this  subject.  The 
very  observations  which  Professor  Forbes  regards  as  proofs 
are  those  of  which  we  require  the  physical  explanation.  It 
is  not  the  viscous  flow,  if  you  please  to  call  it  such,  of 


308  THE  ICE  AND   THE   GLACIER. 

the  glacier  as  a  whole  that  here  concerns  us  ;  but  it 
is  the  quality  of  the  ice  in  virtue  of  which  this  kind  of  mo- 
tion is  accomplished.  Professor  Forbes  sees  this  difference 
clearly  enough  ;  he  speaks  of  "  fissured  ice  "  being  "  flex- 
ible "  in  hand  specimens ;  he  compares  the  glacier  to  a 
mixture  of  ice  and  sand  ;  and  finally,  in  a  more  matured 
paper,  falls  back  for  an  explanation  upon  the  observations 
of  Agassiz  regarding  the  capillaries  of  the  glacier.* 


(15.) 

THE  measurements  of  Agassiz  and  Forbes  completely 
verify  the  anticipations  of  Rendu  ;  but  no  writer  with 
whom  I  am  acquainted  has  added  anything  essential  to 
the  Bishop's  statements  as  to  the  identity  of  glacier  and 
liquid  motion.  He  laid  down  the  conditions  of  the  pro- 
blem with  perfect  clearness,  and,  as  regards  the  distribu- 
tion of  merit,  the  point  to  be  decided  is  the  relative  im- 
portance of  his  idea,  and  of  the  measurements  which  were 
subsequently  made. 

The  observations  on  which  Professor  Forbes  based  the 
analogy  between  a  glacier  and  a  river  are  the  following. 
In  1842  he  fixed  four  marks  upon  the  Mer  de  Glace  a  lit- 
tle below  Montanvert,  the  first  of  which  was  100  yards 
distant  from  the  side  of  the  glacier,  while  the  last  was  at 

*  In  all  that  has  been  written  upon  glaciers  in  this  country  the  above  pas- 
sages from  the  writings  of  Rendu  are  unquoted ;  and  many  who  mingled  very 
warmly  in  the  discussions  of  the  subject  were,. until  quite  recently,  ignorant 
of  their  existence.  I  was  long  in  this  condition  myself,  for  I  never  supposed 
that  passages  which  bear  so  directly  upon  a  point  so  much  discussed,  and  of 
such  cardinal  import,  could  have  been  overlooked  ;  or  that  the  task  of  call- 
ing attention  to  them  should  devolve  upon  myself  nearly  twenty  years  after 
their  publication.  Now  that  they  are  discovered,  I  conceive  no  difference 
of  opinion  can  exist  as  to  the  propriety  of  placing  them  in  their  true  posi- 
tion. 


OBSERVATIONS   OF  FORBES.  309 

the  centre  "  or  a  little  beyond  it."     The  relative  velocity 
of  these  four  points  was  found  to  be 

1.000        1.332        1.356        1.367. 

The  first  observations  were  made  upon  two  of  these  points, 
two  others  being  subsequently  added.  Professor  Forbes 
also  determined  the  velocity  of  two  points  on  the  Glacier 
du  Ge'ant,  and  found  the  ratio  of  motion,  in  the  first 
instance,  to  be  as  14  to  32.  Subsequent  measurements, 
however,  showed  the  ratio  to  be  as  14  to  18,  the  larger 
motion  belonging  to  the  station  nearest  to  the  centre  of 
the  glacier.  These  are  the  only  measurements  which  I 
can  find  in  his  large  work  that  establish  the  swifter  mo- 
tion of  the  centre  of  the  glacier ;  and  in  these  cases  the 
velocity  of  the  centre  is  compared  with  that  of  one  side 
'only.  In  no  instance  that  I  am  aware  of,  either  in  1842 
or  subsequent  years,  did  Professor  Forbes  extend  his 
measurements  quite  across  a  glacier  ;  and  as  regards  com- 
pleteness in  this  respect,  no  observations  hitherto  made 
can  at  all  compare  with  those  executed  at  the  instance  of 
Agassiz  upon  the  glacier  of  the  Aar. 

In  1844  Professor  Forbes  made  a  series  of  interesting 
experiments  on  a  portion  of  the  Mer  de  Glace  near  V Angle. 
He  divided  a  length  of  90  feet  into  45  equal  spaces,  and 
fixed  pins  at  the  end  of  each.  His  theodolite  was  placed 
upon  the  icfe,  and  in  seventeen  days  he  found  that  the  ice 
90  feet  nearer  the  centre  than  the  theodolite  had  moved 
26  inches  past  the  latter.  These  measurements  were  un- 
dertaken for  a  special  object,  and  completely  answered 
the  end  for  which  they  were  intended. 

In  1846  Professor  Forbes  made  another  important  ob- 
servation. Fixing  three  stakes  at  the  heights  of  8,  54, 
and  143  feet  above  the  bed  of  the  glacier,  he  found  that 
in  five  days  they  moved  respectively  2.87,  4.18,  and  4.66 
feet.  The  stake  nearest  the  bed  moved  most  slowly,  thus 


310  MEASUREMENTS  OF  AGASSIZ. 

showing  that  the  ice  is  retarded  by  friction.  This  result 
was  subsequently  verified  by  the  measurements  of  M. 
Martins,  and  by  my  own. 

If  we  add  to  the  above  an  observation  made  during  a 
short  visit  to  the  Aletsch  glacier  in  1844,  which  showed 
its  lateral  retardation,  I  believe  we  have  before  us  the 
whole  of  the  measurements  executed  by  Professor  Forbes, 
which  show  the  analogy  between  the  motion  of  a  glacier 
and  that  of  a  viscous  body. 

Illustrative  of  the  same  point,  we  have  the  elaborate 
and  extensive  series  of  measurements  executed  by  M. 
Wild  under  the  direction  of  M.  Agassiz  upon  the  glacier 
of  the  Aar  in  1842,  1843,  1844,  and  1845,  which  exhibit 
on  a  grand  scale,  and  in  the  most  conclusive  manner,  the 
character  of  the  motion  of  this  glacier ;  and  also  show, 
on  close  examination,  an  analogy  with  fluid  motion  which 
neither  M.  Agassiz  nor  Professor  Forbes  suspected.  The 
former  philosopher  publishes  a  section  in  his  "  Syst^me 
Glaciaire,"  entitled  "  Migrations  of  the  Centre  ; "  in  which 
he  shows  that  the  middle  of  the  glacier  is  not  always  the 
point  of  swiftest  motion.  The  detection  of  this  fact 
demonstrates  the  attention  devoted  by  M.  Agassiz  to  the 
discussion  of  his  observations,  but  he  gives  no  clue  to  the 
cause  of  the  variation.  On  inspecting  the  shape  of  the 
valley  through  which  the  Aar  glacier  moves,  I  find  that 
these  "migrations"  follow  the  law  establislfed  in  1857 
upon  the  Mer  de  Glace,  and  enunciated  at  page  286. 

To  sum  up  this  part  of  the  question  :  —  The  idea  of 
semi-fluid  motion  belongs  entirely  to  Rendu  ;  the  proof  of 
the  quicker  central  flow  belongs  in  part  to  Rendu,  but 
almost  wholly  to  Agassiz  and  Forbes  ;  the  proof  of  the 
retardation  of  the  bed  belongs  to  Forbes  alone  ;  while 
the  discovery  of  the  locus  of  the  point  of  maximum  mo- 
tion belongs,  I  suppose,  to  me. 


"FACTS   AND  PRINCIPLES."  311 

FORBES'S   THEORY. 
(16.) 

THE  formal  statement  of  this  theory  is  given  in  the  fol- 
lowing words  :  — "A  glacier  is  an  imperfect  fluid,  or  vis- 
cous body,  which  is  urged  down  slopes  of  a  certain  inclina- 
tion by  the  mutual  pressure  of  its  parts."  The  consistency 
of  the  glacier  is  illustrated  by  reference  to  treacle,  honey, 
and  tar,  and  the  theory  thus  enunciated  and  exemplified 
is  called  the  "  Viscous  Theory." 

It  has  been  the  subject  of  much  discussion,  and  great 
differences  of  opinion  are  still  entertained  regarding  it. 
Able  and  sincere  men  take  opposite  sides  ;  and  the  extra- 
ordinary number  of  Reviews  which  have  appeared  upon  the 
subject  during  the  last  two  years  show  the  interest  which 
the  intellectual  public  of  England  take  in  the  question. 
The  chief  differences  of  opinion  turn  upon  the  inquiry  as 
to  what  Professor  Forbes  really  meant  when  he  propounded 
the  viscous  theory  ;  some  affirm  one  thing,  some  another, 
and,  singularly  enough,  these  differences  continue,  though 
the  author  of  the  theory  has  at  various  times  published 
expositions  of  his  views. 

The  differences  referred  to  arise  from  the  circumstances 
that  a  sufficient  distinction  has  not  been  observed  between 
facts  and  principles,  and  that  the  viscous  theory  has  assumed 
various  forms  since  its  first  promulgation.  It  has  been 
stated  to  me  that  the  theory  of  Professor  Forbes  is  "  the 
congeries  of  facts  "  which  he  has  discovered.  But  it  is 
quite  evident  that  no  recognition,  however  ample,  of  these 
facts  would  be  altogether  satisfactory  to  Professor  Forbes 
himself.  He  claims  recognition  of  his  theory*  and  no  writer 

*  "Mr.  Hopkins,"  writes  Professor  Forbes,  "has  done  me  the  honour, 
in  the  memoirs  before  alluded  to,  to  mention  with  approbation  my  observa- 


812  VISCOUS   THEORY;  — WHAT  IS  IT? 

with  whom  I  am  acquainted  makes  such  frequent  use  of 
the  term.  What  then  can  the  viscous  theory  mean  apart 
from  the  facts  ?  I  interpret  it  as  furnishing  the  principle 
from  which  the  facts  follow  as  physical  consequences — that 
the  glacier  moves  as  a  river  because  the  ice  is  viscous.  In 
this  sense  only  can  Professor  Forbes's  views  be  called  a 
theory ;  in  any  other,  his  experiments  are  mere  illustra- 
tions of  the  facts  of  glacier  motion,  which  do  not  carry  us 
a  hair's  breadth  towards  their  physical  cause. 

What  then  is  the  meaning  of  viscosity  or  viscidity  ?  I 
have  heard  it  defined  by  men  of  high  culture  as  "  gluey 
tenacity : "  and  such  tenacity  they  once  supposed  a  glacier  to 
possess.  If  we  dip  a  spoon  into  treacle,  honey,  or  tar,  we  can 
draw  the  substance  out  into  filaments,  and  the  same  may  be 
done  with  melted  caoutchouc  or  lava.  All  these  substances 
are  viscous,  and  all  of  them  have  been  chosen  to  illustrate 
the  physical  property  in  virtue  of  which  a  glacier  moves. 
Viscosity  then  consists  in  the  power  of  being  drawn  out 
when  subjected  to  a  force  of  tension,  the  substance,  after 
stretching,  being  in  a  state  of  molecular  equilibrium,  or,  in 
other  words,  devoid  of  that  elasticity  which  would  restore  it 
to  its  original  form.  This  certainly  was  the  idea  attached 
to  Professor  Forbes's  words  by  some  of  his  most  strenuous 
supporters,  and  also  by  eminent  men  who  have  never 
taken  part  in  any  controversy  on  the  subject.  Mr.  Darwin, 
for  example,  speaks  of  felspathic  rocks  being  "  stretched  " 
while  flowing  slowly  onwards  in  a  pasty  condition,  in  pre- 
cisely the  same  manner  as  Professor  Forbes  believes  that 
the  ice  of  moving  glaciers  is  stretched  and  fissured  ;  and 
Professor  Forbes  himself  quotes  these  words  of  Mr.  Dar- 
win as  illustrative  of  his  theory.* 

tions  and  experiments  on  the   subjects   of  glaciers.     He  has  been   more 
sparing  either  in  praise  or  criticism  of  the  theory  which  I  have  founded 
upon  them.    Had  Mr.  Hopkins,"  &c.  —Eighth Letter;  "  Occ.  Papers,"  p.  66. 
*  "  Occ.  Papers,"  p.  92. 


THEORY  TESTED.  313 

The  question  now  before  us  is,  —  Does  a  glacier  ex- 
hibit that  power  of  yielding  to  a  force  of  tension  which 
would  entitle  its  ice  to  be  regarded  as  a  viscous  substance  ? 

With  a  view  to  the  solution  of  this  question  Mr.  Hirst 
took  for  me  the  inclinations  of  the  Mer  de  Glace  and 
all  its  tributaries  in  1857  ;  the  effect  of  a  change  of  incli- 
nation being  always  noted.  I  will  select  from  those  mea- 
surements a  few  which  bear  more  specially  upon  the 
subject  now  under  consideration,  commencing  with  the 
Glacier  des  Bois,  down  which  the  ice  moves  in  that  state 
of  wild  dislocation  already  described.  The  inclination  of 
the  glacier  above  this  cascade  is  5°  10',  and  that  of  the 
cascade  itself  is  22°  20',  the  change  of  inclination  being 
therefore  17°  10'. 

In  Fig.  22  I  have  protracted  the  inclination  of  the  cas- 
cade and  of  the  glacier  above  it ;  the  line  A  B  represent- 


Fig.  22. 

ing  the  former,  and  B  C  the  latter.  Now  a  stream  of  mol- 
ten lava,  of  treacle,  or  tar,  would,  in  virtue  of  its  viscosity, 
be  able  to  flow  over  the  brow  at  B  without  breaking  across ; 
but  this  is  not  the  case  with  the  glacier ;  it  is  so  smashed 
and  riven  in  crossing  this  brow,  that,  to  use  the  words  of 
Professor  Forbes  himself,  "  it  pours  into  the  valley  beneath 
in  a  cascade  of  icy  fragments." 

But  this  reasoning  will  appear  much  stronger  when  we 
revert  to  other  slopes  upon  the  Mer  de  Glace.  For  ex- 
ample, its  inclination  above  1' Angle  is  4°,  and  it  after- 
wards descends  a  slope  of  9°  25',  the  change  of  inclination 
being  5°  25'.  If  we  protract  these  inclinations  to  scale, 


314 


INCLINATIONS   OF   THE   HER   DE   GLACE. 


we  have  the  line  A  B,  Fig.  23,  representing  the  steeper 
slope,  and  B  C  that  of  the  glacier  above  it.     One  would 


Fig.  23. 

surely  think  that  a  viscous  body  could  cross  the  brow  B 
without  transverse  fracture,  but  this  the  glacier  cannot 
do,  and  Professor  Forbes  himself  pronounces  this  portion 
of  the  Mer  de  Glace  impassable.  Indeed  it  was  the  pro- 
found crevasses  here  formed  which  placed  me  in  a  diffi- 
culty already  referred  to.  Higher  up  again,  the  glacier 
is  broken  on  passing  from  a  slope  of  3°  10'  to  one  of  5°. 
Such  observations  show  how  differently  constituted  a  gla- 
cier is  from  a  stream  of  lava  in  a  "  pasty  condition,"  or 
of  treacle,  honey,  tar,  or  melted  caoutchouc,  to  all  which 
it  has  l3een  compared.  In  the  next  section  I  shall  en- 
deavour to  explain  the  origin  of  the  crevasses,  and  shall 
afterwards  make  a  few  additional  remarks  on  the  alleged 
viscosity  of  ice. 


CREVASSES   CAUSED  BY  THE  MOTION.  315 


THE    CREVASSES. 

(17.) 

HAVING  made  ourselves  acquainted  with  the  motion  of 
the  glacier,  we  are  prepared  to  examine  those  rents,  fis- 
sures, chasms,  or,  as  they  are  most  usually  called,  Cre- 
vasses, by  which  all  glaciers  are  more  or  less  intersected. 
They  result  from  the  motion  of  the  glacier,  and  the  laws 
of  their  formation  are  deduced  immediately  from  those  of 
the  motion.  The  crevasses  are  sometimes  very  deep  and 
numerous,  and  apparently  without  law  or  order  in  their 
distribution.  They  cut  the  ice  into  long  ridges,  and  break 
these  ridges  transversely  into  prisms ;  these  prisms  gradu- 
ally waste  away,  assuming,  according  to  the  accidents  of 
their  melting,  the  most  fantastic  forms.  I  have  seen  them 
like  the  mutilated  statuary  of  an  ancient  temple,  like  the 
crescent  moon,  like  huge  birds  with  outstretched  wings, 
like  the  claws  of  lobsters,  and  like  antlered  deer.  Such 
fantastic  sculpture  is  often  to  be  found  on  the  ice  cascades, 
where  the  riven  glacier  has  piled  vast  blocks  on  vaster  pe- 
destals, and  presented  them  to  the  wasting  action  of  sun 
and  air.  In  Fig.  24  I  have  given  a  sketch  of  a  mass  of 
ice  of  this  character,  which  stood  in  1859  on  the  dislocated 
slope  of  the  Glacier  des  Bois. 

It  is  usual  for  visitors  to  the  Montanvert  to  descend  to 
the  glacier,  and  to  be  led  by  their  guides  to  the  edges  of 
the  crevasses,  where,  being  firmly  held,  they  look  down  into 
them ;  but  those  who  have  only  made  their  acquaintance 
in  this  way  know  but  little  of  their  magnitude  and  beauty 
in  the  more  disturbed  portions  of  glaciers.  As  might  be 
expected,  they  have  been  the  graves  of  many  a  moun- 
taineer ;  and  the  skeletons  found  upon  the  glacier  prove 
that  even  the  chamois  itself,  with  its  elastic  muscles  and 


316  FANTASTIC  ICE-MASSES. 

admirable  sureness  of  foot,  is  not  always  safe  among  the 
crevasses.     They  are  grandest  in  the  higher  ice-regions, 


Fig.  24. 

where  the  snow  hangs  like  a  coping  over  their  edges,  and 
the  water  trickling  from  these  into  the  gloom  forms  splendid 
icicles.  The  Gorner  Glacier,  as  we  ascended  it  towards  the 
old  Weissthor,  presents  many  fine  examples  of  such  cre- 
vasses :  the  ice  being  often  torn  in  a  most  curious  and 
irregular  manner.  You  enter  a  porch,  pillared  by  icicles, 
and  look  into  a  cavern  in  the  very  body  of  the  glacier, 
encumbered  with  vast  frozen  bosses  which  are  fringed  all 
round  by  dependent  icicles.  At  the  peril  of  your  life  from 
slipping,  or  from  the  yielding  of  the  stalactites,  you  may 
enter  these  caverns,  and  find  yourself  steeped  in  the  blue 
illumination  of  the  place.  Their  beauty  is  beyond  descrip- 
tion ;  but  you  cannot  deliver  yourself  up,  heart  and  soul,  to 
its  enjoyment.  There  is  a  strangeness  about  the  place  which 
repels  you,  and  not  without  anxiety  do  you  look  from  your 


BIRTH  OF  A   CREVASSE.  317 

ledge  into  the  darkness  below,  through  which  the  sound 
of  subglacial  water  sometimes  rises  like  the  tolling  of  dis- 
tant bells.  You  feel  that,  however  the  cold  splendours 
of  the  place  might  suit  a  purely  spiritual  essence,  they 
are  not  congenial  to  flesh  and  blood,  and  you  gladly 
escape  from  its  magnificence  to  the  sunshine  of  the  world 
above. 

From  their  numbers  it  might  be  inferred  that  the 
formation  of  crevasses  is  a  thing  of  frequent  occurrence 
and  easy  to  observe ;  but  in  reality  it  is  very  rarely  ob- 
served. Simond  was  a  man  of  considerable  experience 
upon  the  ice,  but  the  first  crevasse  he  ever  saw  formed 
was  during  the  setting  out  of  one  of  our  lines,  when  a 
narrow  rent  opened  beneath  his  feet,  and  propagated  itself 
through  the  ice  with  loud  cracking  for  a  distance  of  50 
or  60  yards.  Crevasses  always  commence  in  this  way  as 
mere  narrow  cracks,  which  open  very  slowly  afterwards. 
I  will  here  describe  the  only  case  of  crevasse-forming 
which  has  come  under  my  direct  observation. 

On  the  31st  of  July,  1857,  Mr.  Hirst  and  myself,  having 
completed  our  day's  work,  were  standing  together  upon 
the  Glacier  du  Gdant,  when  a  loud  dull  sound,  like  that 
produced  by  a  heavy  blow,  seemed  to  issue  from  the  body 
of  the  ice  underneath  the  spot  on  which  we  stood.  This 
was  succeeded  by  a  series  of  sharp  reports,  which  were 
heard  sometimes  above  us,  sometimes  below  us,  sometimes 
apparently  close  under  our  feet,  the  intervals  between  the 
louder  reports  being  filled  by  a  low  singing  noise.  We 
turned  hither  and  thither  as  the  direction  of  the  sounds 
varied  ;  for  the  glacier  was  evidently  breaking  beneath 
our  feet,  though  we  could  discern  no  trace  of  rupture. 
For  an  hour  the  sounds  continued  without  our  being  able 
to  discover  their  source  ;  this  at  length  revealed  itself  by 
a  rush  of  air-bubbles  from  one  of  the  little  pools  upon 
the  surface  of  the  glacier,  which  was  intersected  by 


318  MECHANICAL  ORIGIN. 

the  newly-formed  crevasse.  We  then  traced  it  for  some 
distance  up  and  down,  but  hardly  at  any  place  was  it 
sufficiently  wide  to  permit  the  blade  of  my  penknife 
to  enter  it.  M.  Agassiz  has  given  an  animated  descrip- 
tion of  the  terror  of  his  guides  upon  a  similar  occasion, 
and  there  was  an  element  of  awe  in  our  own  feelings 
as  we  heard  the  evening  stillness  of  the  glacier  thus 
disturbed. 

With  regard  to  the  mechanical  origin  of  the  crevasses 
the  most  vague  and  untenable  notions  had  been  enter- 
tained until  Mr.  Hopkins  published  his  extremely  valu- 
able papers.  To  him,  indeed,  we  are  almost  wholly  in- 
debted for  our  present  knowledge  of  the  subject,  my  own 
experiments  upon  this  portion  of  the  glacier-question 
being  for  the  most  part  illustrations  of  the  truth  of  his 
reasoning.  To  understand  the  fissures  in  their  more 
complex  aspects  it  is  necessary  that  we  should  commence 
with  their  elements.  I  shall  deal  with  the  question  in 
my  own  way,  adhering,  however,  to  the  mechanical  prin- 
ciples upon  which  Mr.  Hopkins  has  based  his  exposition. 


Fig.  25. 

Let  A  B,  C  D,  be  the  bounding  sides  of  a  glacier  moving 
in  the  direction  of  the  arrow  ;  let  m,  n  be  two  points  upon 
the  ice,  one,  m,  close  to  the  retarding  side  of  the  valley, 
and  the  other,  n,  at  some  distance  from  it.  After  a 
certain  time,  the  point  m  will  have  moved  downwards  to 
m'9  but  in  consequence  of  the  swifter  movement  of  the 


LINE   OF  GREATEST   STRAIN.  319 

parts  at  a  distance  from  the  sides,  n  will  have  moved  in 
the  same  time  to  n'.  Thus  the  line  m  n,  instead  of  being 
at  right  angles  to  the  glacier,  takes  up  the  oblique  posi- 
tion m1  n' ;  but  to  reach  from  m'  to  n1  the  line  m  n  would 
have  to  stretch  itself  considerably  ;  every  other  line  that 
we  can  draw  upon  the  ice  parallel  to  m1  n1  is  in  a  similar 
state  of  tension  ;  or,  in  other  words,  the  sides  of  the  glacier 
are  acted  upon  by  an  oblique  pull  towards  the  centre. 
Now,  Mr.  Hopkins  has  shown  that  the  direction  in  which 
this  oblique  pull  is  strongest  encloses  an  angle  of  45°  with 
the  side  of  the  glacier. 

What  is  the  consequence  of  this  ?  Let  A  B,  C  D,  fig.  26, 


Fig.  26. 

represent,  as  before,  the  sides  of  the  glacier,  moving  in 
the  direction  of  the  arrow  ;  let  the  shading  lines  enclose 
an  angle  of  45°  with  the  sides.  Along  these  lines  the 
marginal  ice  suffers  the  greatest  strain,  and  consequently 
across  these  lines,  and  at  right  angles  to  them,  the  ice 
tends  to  break  and  to  form  marginal  crevasses.  The 
lines,  o  p,  o  p,  mark  the  direction  of  these  crevasses  ; 
they  are  at  right  angles  to  the  line  of  greatest  strain,  and 
hence  also  enclose  an  angle  of  45°  with  the  side  of  the 
valley,  being  obliquely  pointed  upwards. 

This  latter,  result  is  noteworthy ;  it  follows  from  the 

mechanical  data  that  the  swifter  motion  of  the  centre 

tends  to  produce  marginal  crevasses  which  are  inclined 

from  the  side  of  the  glacier  towards  its  source,  and  not 

21 


320       MARGINAL  AND   TRANSVERSE   CREVASSES. 

towards  its  lower  extremity.  But  when  we  look  down 
upon  a  glacier  thus  crevassed,  the  first  impression  is  that 
the  sides  have  been  dragged  down,  and  have  left  the  cen- 
tral portions  behind  them  ;  indeed,  it  was  this  very  ap- 
pearance that  led  M.  de  Charpentier  and  M.  Agassiz  into 
the  error  of  supposing  that  the  sides  of  a  glacier  moved 
more  quickly  than  its  middle  portions  ;  and  it  was  also 
the  delusive  aspect  of  the  crevasses  which  led  Professor 
Forbes  to  infer  the  slower  motion  of  the  eastern  side  of 
the  Mer  de  Glace. 

The  retardation  of  the  ice  is  most  evident  near  the 
sides  ;  in  most  cases,  the  ice  for  a  considerable  distance 
right  and  left  of  the  central  line  moves  with  .a  sensibly 
uniform  velocity  ;  there  is  no  dragging  of  the  particles 
asunder  by  a  difference  of  motion,  and,  consequently,  a 
compact  centre  is  perfectly  compatible  with  fissured  sides. 
Nothing  is  more  common  than  to  see  a  glacier  with  its 
sides  deeply  cut,  and  its  central  portions  compact ;  this, 
indeed,  is  always  the  case  where  the  glacier  moves  down 
a  bed  of  uniform  inclination. 

But  supposing  that  the  bed  is  not  uniform,  —  that  the 
valley  through  which  the  glacier  moves  changes  its  incli- 
nation abruptly,  so  as  to  compel  the  ice  to  pass  over  a 
brow ;  the  glacier  is  then  circumstanced  like  a  stick 
which  we  try  to  break  by  holding  its  two  ends  and  press- 
ing it  against  the  knee.  The  brow,  where  the  bed 
changes  its  inclination,  represents  the  knee  in  the  case 
of  the  stick,  while  the  weight  of  the  glacier  itself  is  the 
force  that  tends  to  break  it.  It  breaks  ;  and  fissures  are 
formed  across  the  glacier,  which  are  hence  called  trans- 
verse crevasses. 

No  glacier  with  which  I  am  acquainted  illustrates  the 
mechanical  laws  just  developed  more  clearly  and  fully 
than  the  Lower  glacier  of  Grindelwald.  Proceeding  along 
the  ordinary  track  beside  the  glacier,  at  about  an  hour's 


GRINDELWALD   GLACIEK.  321 

distance  from  the  village  the  traveller  reaches  a  point 
whence  a  view  of  the  glacier  is  obtained  from  the 
heights  above  it.  The  marginal  fissures  are  very  cleanly 
cut,  and  point  nearly  in  the  direction  already  indicated ; 
the  glacier  also  changes  its  inclination  several  times 
along  the  distance  within  the  observer's  view.  On  cross- 
ing each  brow  the  glacier  is  broken  across,  and  a  series  of 
transverse  crevasses  is  formed,  which  follow  each  other 
down  the  slope.  At  the  bottom  of  the  slope  tension 
gives  place  to  pressure,  the  walls  of  the  crevasses  are 
squeezed  together,  and  the  chasms  closed  up.  They 
remain  closed  along  the  comparatively  level  space  which 
stretches  between  the  base  of  one  slope  and  the  brow  of 
the  next ;  but  here  the  glacier  is  again  transversely  bro- 
ken, and  continues  so  until  the  base  of  the  second  slope 
is  reached,  where  longitudinal  pressure  instead  of  longi- 
tudinal strain  begins  to  act,  and  the  fissures  are  closed 
as  before.  In  Fig.  27  A  I  have  given  a  sketchy  section  of 
a  portion  of  the  glacier,  illustrating  the  formation  of  the 
crevasses  at  the  top  of  a  slope,  and  their  subsequent 
obliteration  at  its  base. 

Another  effect  is  here  beautifully  shown,  namely,  the 
union  of  the  transverse  and  marginal  crevasses  to  form 
continuous  fissures  which  stretch  quite  across  the  glacier. 
Fig.  27  B  will  illustrate  my  meaning,  though  very  imper- 
fectly ;  it  represents  a  plan  of  a  portion  of  the  Lower  Grin- 
delwald  glacier,  with  both  marginal  and  transverse  fissures 
drawn  upon  it.  I  have  placed  it  under  the  section  so  that 
each  part  of  it  may  show  in  plan  the  portion  of  the  glacier 
which  is  shown  in  section  immediately  above  it.  It  shows 
how  the  marginal  crevasses  remain  after  the  compression 
of  the  centre  has  obliterated  the  transverse  ones ;  and  how 
the  latter  join  on  to  the  former,  so  as  to  form  continuous 
fissures,  which  sweep  across  the  glacier  in  vast  curves, 
with  their  convexities  turned  upwards.  The  illusion  be- 


322 


COMPRESSION  AND  TENSION. 


fore  referred  to  is  here  strengthened ;  the  crevasses  turn, 
so  to  say,  against  the  direction  of  motion,  instead  of  form- 


Fig.  27  B. 


ing  loops,  with  their  convexities  pointing  downwards,  and 
thus  would  impress  a  person  unacquainted  with  the  me- 
chanical data  with  the  idea  that  the  glacier  margins  moved 
more  quickly  than  the  centre.  The  figures  are  intended 
to  convey  the  idea  merely ;  on  the  actual  slopes  of  the 
glacier  between  twenty  and  thirty  chasms  may  be  counted  : 
the  word  "  compression"  also  ought  to  have  been  limited 
to  the  level  portions  of  the  sketch. 

Besides  the  two  classes  of  fissures  mentioned  we  often 
find  others,  which  are  neither  marginal  nor  transverse. 
The  terminal  portions  of  many  glaciers,  for  example,  are 
in  a  state  of  compression ;  the  snout  of  the  glacier  abuts 
against  the  ground,  and  having  to  bear  the  thrust  of  the 
mass  behind  it,  if  it  have  room  to  expand  laterally,  the  ice 


LONGITUDINAL   CREVASSES.  323 

will  yield,  and  longitudinal  crevasses  will  be  formed.  They 
are  of  very  common  occurrence,  but  the  finest  example 
of  the  kind  is  perhaps  exhibited  by  the  glacier  of  the 
Rhone.  After  escaping  from  the  steep  gorge  which  holds 
the  cascade,  this  glacier  encounters  the  bottom  of  a  com- 
paratively wide  and  level  valley  ;  the  resistance  to  its  for- 
ward motion  is  augmented,  while  its  ability  to  expand 
laterally  is  increased  ;  it  has  to  bear  a  longitudinal  thrust, 
and  it  splits  at  right  angles  to  the  pressure.  A  series  of 
fissures  is  thus  formed,  the  central  ones  of  which  are  truly 
longitudinal ;  but  on  each  side  of  the  central  line  the  cre- 
vasses diverge,  and  exhibit  a  fan-like  arrangement.  This 
disposition  of  the  fissures  is  beautifully  seen  from  the  sum- 
mit of  the  Mayenwand  on  the  Grimsel  Pass. 

Here  then  we  have  the  elements,  so  to  spea,k,  of  glacier- 
crevassing,  and  through  their  separate  or  combined  action 
the  most  fantastic  cutting  up  of  a  glacier  may  be  effected. 
And  see  how  beautifully  these  simple  principles  enable 
us  to  account  for  the  remarkable  crevassing  of  the 
eastern  side  of  the  Mer 
de  Glace.  Let  A  B,  CD, 
be  the  opposite  sides  of  a 
portion  of  the  glacier,  near 
the  Montanvert ;  c  D  being 
east,  and  A  B  west,  the 
glacier  moving  in  the  di-  A  Montanvert 

rection  of  the  arrow  ;  let 

the  points  m  n  represent  the  extremities  of  our  line  of 
stakes,  and  let  us  suppose  an  elastic  string  stretched  across 
the  glacier  from  one  to  the  other.  We  have  proved  that 
the  point  of  maximum  motion  here  lies  much  nearer  to 
the  side  c  D  than  to  A  B.  Let  o  be  this  point,  and,  seizing 
the  string  at  o,  let  it  be  drawn  in  the  direction  of  motion 
until  it  assumes  the  position,  m,  o',  n.  It  is  quite  evident 
that  o'  n  is  in  a  state  of  greater  tension  than  o'  m,  and  the 


324  CREVASSING  OF   CONVEX   SIDE. 

ice  at  the  eastern  side  of  the  Mer  de  Glace  is  in  a  precisely 
similar  mechanical  condition.  It  suffers  a  greater  strain 
than  the  ice  at  the  opposite  side  of  the  valley,  and  hence  is 
more  fissured  and  broken.  Thus  we  see  that  the  crevassing 
of  the  eastern  side  of  the  glacier  is  a  simple  consequence 
of  the  quicker  motion  of  that  side,  and  does  not,  as  hitherto 
supposed,  demonstrate  its  slower  motion.  The  reason  why 
the  eastern  side  of  the  glacier,  as  a  whole,  is  much  more 
fissured  than  the  western  side  is,  that  there  are  two  long 
segments  which  turn  their  convex  curvature  eastward,  and 
only  one  segment  of  the  glacier  which  turns  its  convexity 
westward. 

The  lower  portion  of  the  Rhone  glacier  sweeps  round 
the  side  of  the  valley  next  the  Furca,  and  turns  through- 
out a  convex  curve  to  this  side  :  the  crevasses  here  are 
wide  and  frequent,  while  they  are  almost  totally  absent  at 
the  opposite  side  of  the  glacier.  The  Lower  Grindelwald 
glacier  turns  at  one  place  a  convex  curve  towards  the 
Eiger,  and  is  much  more  fissured  at  that  side  than  at 
the  opposite  one ;  indeed,  the  fantastic  ice-splinters,  col- 
umns, and  minarets,  which  are  so  finely  exhibited  upon 
this  glacier,  are  mainly  due  to  the  deep  crevassing  of  the 
convex  side.  Numerous  other  illustrations  of  the  law  might, 
I  doubt  not,  be  discovered,  and  it  would  be  a  pleasant  and 
iiseful  occupation  to  one  who  takes  an  interest  in  the  sub- 
ject, to  determine,  by  strict  measurements  upon  other  gla- 
ciers, the  locus  of  the  point  of  maximum  motion,  and 
to  observe  the  associated  mechanical  effects. 

The  appearance  of  crevasses  is  often  determined  by  cir- 
cumstances more  local  and  limited  than  those  above  indi- 
cated ;  a  boss  of  rock,  a  protuberance  on  the  side  of  the 
flanking  mountain,  anything,  in  short,  which  checks  the 
motion  of  one  part  of  the  ice  and  permits  an  adjacent 
portion  to  be  pushed  away  from  it,  produces  crevasses. 
Some  valleys  are  terminated  by  a  kind  of  mountain-circus 


BERGSCHRUNDS.  325 

with  steep  sides,  against  which  the  snow  rises  to  a  con- 
siderable height.  As  the  mass  is  urged  downwards,  the 
lower  portion  of  the  snow-slope  is  often  torn  away  from 
its  higher  portion,  and  a  chasm  is  formed,  which  usually 
extends  round  the  head  of  the  valley.  To  such  a  crevasse 
the  specific  name  Berg-schrund  is  applied  in  the  Bernese 
Alps ;  I  have  referred  to  one  of  them  in  the  account  of 
the  "  Passage  of  the  Strahleck." 


(18.) 

THE  phenomena  described  and  accounted  for  in  the  last 
chapter  have  a  direct  bearing  upon  the  question  of  visco- 
sity. In  virtue  of  the  quicker  central  flow  the  lateral  ice 
is  subject  to  an  oblique  strain  ;  but,  instead  of  stretching, 
it  breaks,  and  marginal  crevasses  are  formed.  We  also 
see  that  a  slight  curvature  in  the  valley,  by  throwing  an 
additional  strain  upon  one  half  the  glacier,  produces  an 
augmented  crevassing  of  that  side. 

But  it  is  known  that  a  substance  confessedly  viscous  may 
be  broken  by  a  sudden  shock  or  strain.  Professor  Forbes 
justly  observes  that  sealing-wax  at  moderate  temperatures 
will  mould  itself  (with  time)  to  the  most  delicate  inequa- 
lities of  the  surface  on  which  it  rests,  but  may  at  the  same 
time  be  shivered  to  atoms  by  the  blow  of  a  hammer. 
Hence,  in  order  to  estimate  the  weight  of  the  objection 
that  a  glacier  breaks  when  subjected  to  strain,  we  must 
know  the  conditions  under  which  the  force  is  applied. 

The  Mer  de  Glace  has  been  shown  (p.  287)  to  move 
through  the  neck  of  the  valley  at  Trelaporte  at  the  rate  of 
twenty  inches  a  day.  Let  the  sides  of  this  page  represent 
the  boundaries  of  the  glacier  at  Trdlaporte,  and  any  one  of 
its  lines  of  print  a  transverse  slice  of  ice.  Supposing  the  line 


326  NUMERICAL  TEST   OF  VISCOSITY. 

to  move  down  the  page  as  the  slice  of  ice  moves  down  the 
valley,  then  the  bending  of  the  ice  in  twenty-four  hours, 
shown  on  such  a  scale,  would  only  be  sufficient  to  push 
forward  the  centre  in  advance  of  the  sides  by  a  very  small 
fraction  of  the  width  of  the  line  of  print.  To  such  an 
extremely  gradual  strain  the  ice  is  unable  to  accommodate 
itself  without  fracture. 

Or,  referring  to  actual  numbers  :  —  the  stake  No.  15  on 
our  5th  line,  page  284,  stood  on  the  lateral  moraine  of  the 
Mer  de  Glace ;  and  between  it  and  No.  14  a  distance  of 
190  feet  intervened.      Let  A  B,  Fig.  29,  be  the  side  of  the 
glacier,  moving  in  the  direction  of  the  arrow, 
and  let  a  b  c  d  be  a  square  upon  the  glacier 
with  a  side  of  190  feet.      The  whole  square 
moves  with  the  ice,  but  the  side  b  d  moves 
quickest ;    the  point  a   moving   10   inches, 
while  b  moves  14.75  inches  in  24  hours  ;  the 
differential  motion  therefore  amounts  to  an 
inch   in   five    hours.      Let  a  b'  d'  c   be   the 
shape  of  the  figure  after  five  hours'  motion  ; 
then  the  line  a  b  would  be  extended  to  a  b' 
rig.  29.        and  cd  to  c  d' . 

The  extension  of  these  lines  does  not  however  express 
the  maximum  strain  to  which  the  ice  is  subjected.  Mr. 
Hopkins  has  shown  that  this  takes  place  along  the  line  a  d ; 
in  five  hours  then  this  line,  if  capable  of  stretching,  would 
be  stretched  to  a  d1.  From  the  data  given  every  boy  who 
has  mastered  the  47th  Proposition  of  the  First  Book  of  Eu- 
clid can  find  the  length  both  of  a  d  and  a  d1 ;  the  former  is 
3224.4  inches,  and  the  latter  is  3225.1,  the  difference  be- 
tween them  being  seven-tenths  of  an  inch. 

This  is  the  amount  of  yielding  required  from  the  ice 
in  five  hours,  but  it  cannot  grant  this  ;  the  glacier  breaks, 
and  numerous  marginal  crevasses  are  formed.  It  must 
not  be  forgotten  that  the  evidence  here  adduced  merely 


STRETCHING  OF  ICE  NOT  PROVED.  327 

shows  what  ice  cannot  do ;  what  it  can  do  in  the  way  of 
viscous  yielding  we  do  not  know :  there  exists  as  yet  no 
single  experiment  on  great  masses  or  small  to  show  that 
ice  possesses  in  any  sensible  degree  that  power  of  being 
drawn  out  which  seems  the  very  essence  of  viscosity. 

I  have  already  stated  that  the  crevasses,  on  their  first 
formation,  are  exceedingly  narrow  rents,  which  widen  very 
slowly.  The  new  crevasse  observed  by  our  guide  required 
several  days  to  attain  a  width  of  three  inches ;  while  that 
observed  by  Mr.  Hirst  and  myself  did  not  widen  a  single 
inch  in  three  days.  This,  I  believe,  is  the  general  charac- 
ter of  the  crevasses  ;  they  form  suddenly  and  open  slowly. 
Both  facts  are  at  variance  with  the  idea  that  ice  is  vis- 
cous ;  for  were  this  substance  capable  of  stretching  at  the 
slow  rate  at  which  the  fissures  widen,  there  would  be  no 
necessity  for  their  formation. 

It  cannot  be  too  clearly  and  emphatically  stated  that 
the  proved  fact  of  a  glacier  conforming  to  the  law  of  semi- 
fluid motion  is  a  thing  totally  different  from  the  alleged 
fact  of  its  being  viscous.  Nobody  since  its  first  enuncia- 
tion disputed  the  former.  I  had  no  doubt  of  it  when  I 
repaired  to  the  glaciers  in  1856  ;  and  none  of  the  eminent 
men  who  have  discussed  this  question  with  Professor 
Forbes  have  thrown  any  doubt  upon  his  measurements. 
It  is  the  assertion  that  small  pieces  of  ice  are  proved  to 
be  viscous*  by  the  experiments  made  upon  glaciers,  and 
the  consequent  impression  left  upon  the  public  mind  — 
that  ice  possesses  the  "gluey  tenacity"  which  the  term 
viscous  suggests — to  which  these  observations  are  meant 
to  apply. 

*  "  The  viscosity,  though  it  cannot  be  traced  in  the  parts  if  very  minute, 
nevertheless  exists  there,  as  unequivocally  proved  by  experiments  on  the  large 
scale."  —  Forbes  in  "Phil.  Mag.,"  vol.  x.  p.  301. 


328       CONNEXION  OF  NATURAL  FORCES. 

HEAT  AND  WORK. 

(19.) 

GREAT  scientific  principles,  though  usually  announced 
by  individuals,  are  often  merely  the  distinct  expression  of 
thoughts  and  convictions  which  had  long  been  entertained 
by  all  advanced  investigators.  Thus  the  more  profound 
philosophic  thinkers  had  long  suspected  a  certain  equiva- 
lence and  connexion  between  the  various  forces  of  nature ; 
experiment  had  shown  the  direct  connexion  and  mutual 
convertibility  of  many  of  them,  and  the  spiritual  insight, 
which,  in  the  case  of  the  true  experimenter,  always  sur- 
rounds and  often  precedes  the  work  of  his  hands,  re- 
vealed more  or  less  plainly  that  natural  forces  either  had 
a  common  root,  or  that  they  formed  a  circle,  whose  links 
were  so  connected  that  by  starting  from  any  one  of  them 
we  could  go  through  the  circuit,  and  arrive  at  the  point 
from  which  we  set  out.  For  the  last  eighteen  years 
this  subject  has  occupied  the  attention  of  some  of  the 
ablest  natural  philosophers,  both  in  this  country  and  on 
the  Continent.  The  connexion,  however,  which  has  most 
occupied  their  minds  is  that  between  heat  and  work;  the 
absolute  numerical  equivalence  of  the  two  having,  I 
believe,  been  first  announced  by  a  German  physician 
named  Meyer,  and  experimentally  proved  in  this  country 
by  Mr.  Joule. 

A  lead  bullet  may  be  made  hot  enough  to  burn  the 
hand,  by  striking  it  with  a  hammer,  or  by  rubbing  it  against 
a  board  ;  a  clever  blacksmith  can  make  a  nail  red-hot  by 
hammering  it ;  Count  Rumford  boiled  water  by  the  heat 
developed  in  the  boring  of  cannon,  and  inferred  from  the 
experiment  that  heat  was  not  what  it  was  generally 


MECHANICAL  EQUIVALENT  OF  HEAT.      329 

supposed  to  be,  an  imponderable  fluid,  but  a  kind  of  mo- 
tion generated  by  the  friction.  Now  Mr.  Joule's  experi- 
ments enable  us  to  state  the  exact  amount  of  heat  which 
a  definite  expenditure  of  mechanical  force  can  originate. 
I  say  originate,  not  drag  from  any  hiding-place  in  which 
it  had  concealed  itself,  but  actually  bring  into  existence, 
so  that  the  total  amount  of  heat  in  the  universe  is  thereby 
augmented.  If  a  mass  of  iron  fall  from  a  tower  770  feet 
in  height,  we  can  state  the  precise  amount  of  heat  devel- 
oped by  its  collision  with  the  earth.  Supposing  all  the 
heat  thus  generated  to  be  concentrated  in  the  iron  itself, 
its  temperature  would  thereby  be  raised  nearly  10°  Fahr. 
Gravity  in  this  case  has  expended  a  certain  amount  of 
force  in  pulling  the  iron  to  the  earth,  and  this  force  is  the 
mechanical  equivalent  of  the  heat  generated.  Further- 
more, if  we  had  a  machine  so  perfect  as  to  enable  iis  to- 
apply  all  the  heat  thus  produced  to  the  raising  of  a 
weight,  we  should  be  able,  by  it,  to  lift  the  mass  of  iron 
to  the  precise  point  from  which  it  fell. 

But  the  heat  cannot  lift  the  weight  and  still  continue 
heat ;  this  is  the  peculiarity  of  the  modern  view  of  the 
matter.  The  heat  is  consumed,  used  lip,  it  is  no  longer 
heat ;  but  instead  of  it  we  have  a  certain  amount  of  gravi- 
tating force  stored  up,  which  is  ready  to  act  again,  and  to 
regenerate  the  heat  when  the  weight  is  let  loose.  In  fact, 
when  the  falling  weight  is  stopped  by  the  earth,  the  mo- 
tion of  its  mass  is  converted  into  a  motion  of  its  mole- 
cules ;  when  the  weight  is  lifted  by  heat,  molecular  motion 
is  converted  into  ordinary  mechanical  motion,  but  for 
every  portion  of  either  of  them  brought  into  existence 
an  equivalent  portion  of  the  other  must  be  consumed. 

What  is  true  for  masses  is  also  true  for  atoms.  As  the 
earth  and  the  piece  of  iron  mutually  attract  each  other, 
and  produce  heat  by  their  collision,  so  the  carbon  of  a 
burning  candle  and  the  oxygen  of  the  surrounding  air 


330  HEAT  PEODUCED  IF  THE  EARTH  STRUCK  THE  SUN. 

mutually  attract  each  other  ;  they  rush  together,  and  on 
collision  the  arrested  motion  becomes  heat.  In  the  former 
case  we  have  the  conversion  of  gravity  into  heat,  in  the 
latter,  the  conversion  of  chemical  affinity. into  heat; 
but  in  each .  case  the  process  consists  in  the  generation 
of  motion  by  attraction,  and  the  subsequent  change  of 
that  motion  into  motion  of  another  kind.  Mechanically 
considered,  the  attraction  of  the  atoms  and  its  results  is 
precisely  the  same  as  the  attraction  of  the  earth  and 
weight  and  its  results. 

But  what  is  true  for  an  atom  is  also  true  for  a  planet  or 
a  sun.  Supposing  our  earth  to  be  brought  to  rest  in  her 
orbit  by  a  sudden  shock,  we  are  able  to  state  the  exact 
amount  of  heat  which  would  be  thereby  generated.  The 
consequence  of  the  earth's  being  thus  brought  to  rest  would 
be  that  it  would  fall  into  the  sun,  and  the  amount  of  heat 
which  would  be  generated  by  this  second  collision  is  also 
calculable.  Heimholtz  has  calculated  that  in  the  former 
case  the  heat  generated  would  be  equal  to  that  produced 
by  the  combustion  of.  fourteen  earths  of  solid  coal,  and  in 
the  latter  case  the  amount  would  be  400  times  greater. 

Whenever  a  weight  is  lifted  by  a  steam-engine  in  oppo- 
sition to  the  force  of  gravity,  an  amount  of  heat  is  consumed 
equivalent  to  the  work  done  ;  and  whenever  the  molecules 
of  a  body  are  shifted  in  opposition  to  their  mutual  attrac- 
tions work  is  also  performed,  and  an  equivalent  amount  of 
heat  is  consumed.  Indeed  the  amount  of  work  done  in  the 
shifting  of  the  molecules  of  a  body  by  heat,  when  expressed 
in  ordinary  mechanical  work,  is  perfectly  enormous.  The 
lifting  of  a  heavy  weight  to  the  height  of  1,000  feet  may 
be  as  nothing  compared  with  the  shifting  of  the  atoms  of  a 
body  by  an  amount  so  small  that  our  finest  means  of  meas- 
urement hardly  enable  us  to  determine  it.  Different  bodies 
give  heat  different  degrees  of  trouble,  if  I  may  use  the  term, 
in  shifting  their  atoms  and  putting  them  in  new  places. 


SHIFTING   OF  ATOMS.  331 

Iron  gives  more  trouble  than  lead ;  and  water  gives  far  more 
trouble  than  either.  The  heat  expended  in  this  molecular 
work  is  lost  as  heat :  it  does  not  show  itself  as  temperature. 
Suppose  the  heat  produced  by  the  combustion  of  an  ounce 
of  candle  to  be  concentrated  in  a  pound  of  iron,  a  certain 
portion  of  that  heat  would  go  to  perform  the  molecular 
work  to  which  I  have  referred,  and  the  remainder  would 
be  expended  in  raising  the  temperature  of  the  body  ;  and 
if  the  same  amount  of  heat  were  communicated  to  a  pound 
of  iron  and  to  a  pound  of  lead,  the  balance  in  favour  of 
temperature  would  be  greater  in  the  latter  case  than  in  the 
former,  because  the  heat  would  have  less  molecular  work 
to  do  ;  the  lead  would  become  more  heated  than  the  iron. 
To  raise  a  pound  of  iron  a  certain  number  of  degrees  in 
temperature  would,  in  fact,  require  more  than  three  times 
the  absolute  quantity  of  heat  which  would  be  required  to 
raise  a  pound  of  lead  the  same  number  of  degrees.  Con- 
versely, if  we  place  the  pound  of  iron  and  the  pound  of  lead, 
heated  to  the  same  temperature,  in  ice,  we  shall  find  that 
the  quantity  of  ice  melted  by  the  iron  will  be  more  than 
three  times  that  melted  by  the  lead.  In  fact,  the  greater 
amount  of  molecular  work  invested  in  the  iron  now  comes 
into  play,  the  atoms  again  obey  their  own  powerful  forces, 
and  an  amount  of  heat  corresponding  to  the  energy  of 
these  forces  is  generated. 

This  molecular  work  is  that  which  has  usually  been 
called  specific  heat,  or  capacity  for  heat.  According  to 
the  materialistic  view  of  heat,  bodies  are  figured  as  spon- 
ges, and  heat  a  kind  of  fluid  absorbed  by  them,  different 
bodies  possessing  different  powers  of  absorption.  Accord- 
ing to  the  dynamic  view,  as  already  explained,  heat  is  re- 
garded as  a  motion,  and  capacity  for  heat  indicates  the 
quantity  of  that  motion  consumed  in  internal  changes. 

The  greatest  of  these  changes  occurs  when  a  body  passes 
from  one  state  of  aggregation  to  another,  from  the  solid 


332         HEAT   CONSUMED   IN  MOLECULAR  WORK. 

to  the  liquid,  or  from  the  liquid  to  the  aeriform  state ;  and 
the  quantity  of  heat  required  for  such  changes  is  often 
enormous.  To  convert  a  pound  of  ice  at  32°  Fahr.  into 
water  at  the  same  temperature  would  require  an  amount 
of  heat  competent,  if  applied  as  mechanical  force,  to  lift 
the  same  pound  of  ice  to  a  height  of  110,000  feet  ;  it 
would  raise  a  ton  of  ice  nearly  50  feet,  or  it  would  lift 
between  49  and  50  tons  to  a  height  of  one  foot  above  the 
earth's  surface.  To  convert  a  pound  of  water  at  212°  into 
a  pound  of  steam  at  the  same  temperature  would  require 
an  amount  of  heat  which  would  perform  nearly  seven 
times  the  amount  of  mechanical  work  just  mentioned. 

This  heat  is  entirely  expended  in  interior  work*  and 
does  nothing  towards  augmenting  the  temperature ;  the 
water  is  at  the  temperature  of  the  ice  which  produced  it, 
both  are  32° ;  and  the  steam  is  at  the  temperature  of  the 
water  which  produced  it,  both  are  212°.  The  whole  of 
the  heat  is  consumed  in  producing  the  change  of  aggrega- 
tion ;  I  say  "  consumed"  not  hidden  or  "  latent"  in  either 
the  water  or  the  steam,  but  absolutely  nonexistent  as  heat. 
The  molecular  forces,  however,  which  the  heat  has  sacri- 
ficed itself  to  overcome,  are  able  to  reproduce  it ;  the  water 
in  freezing  and  the  steam  in  condensing  give  out  the  ex- 
act amount  of  heat  which  they  consumed  when  the  change 
of  aggregation  was  in  the  opposite  direction. 

At  a  temperature  of  several  degrees  below  its  freezing 
point  ice  is  much  harder  than  at  32°.  I  have  more  than 
once  cooled  a  sphere  of  the  substance  in  a  bath  of  solid 
carbonic  acid  and  ether  to  a  temperature  of  100°  below  the 
freezing  point.  During  the  time  of  cooling  the  ice  crackled 
audibly  from  its  contraction,  and  afterwards  it  quite  resisted 
the  edge  of  a  knife  ;  while  at  32°  it  may  be  cut  or  crushed 
with  extreme  facility.  The  cold  sphere  was  subjected  to 

*  I  borrow  this  term  from  Professor  Clausius's  excellent  papers  on  the 
Dynamical  Theory  of  Heat. 


ICE  NEAR   THE  MELTING  POINT.  833 

pressure  ;  it  broke  with  the  detonation  of  a  vitreous  body, 
and  was  taken  from  the  press  a  white  opaque  powder ; 
which,  on  being  subsequently  raised  to  32°  and  again  com- 
pressed, was  converted  into  a  pellucid  slab  of  ice. 

But  before  the  temperature  of  32°  is  quite  attained,  ice 
gives  evidence  of  a  loosening  of  its  crystalline  texture. 
Indeed  the  unsoundness  of  ice  at  and  near  its  melting 
point  has  been  long  known.  Sir  John  Leslie,  for  example, 
states  that  ice  at  32°  \sfriable;  and  every  skater  knows  how 
rotten  ice  becomes  before  it  thaws.  M.  Person  has  further 
shown  that  the  latent  heat  of  ice,  that  is  to  say,  the  quantity 
of  heat  necessary  for  its  liquefaction,  is  not  quite  expressed 
by  the  quantity  consumed  in  reducing  ice  at  32°  to  the  liquid 
state.  The  heat  begins  to  be  rendered  latent,  or  in  other 
words  the  change  of  aggregation  commences,  a  little  before 
the  substance  reaches  32°,  —  a  conclusion  which  is  illus- 
trated and  confirmed  by  the  deportment  of  melting  ice 
under  pressure. 

In  reference  to  the  above  result  Professor  Forbes 
writes  as  follows  :  —  "I  have  now  to  refer  to  a  fact  .... 
established  by  a  French  experimenter,  M.  Person,  who 
appears  not  to  have  had  even  remotely  in  his  mind  the 
theory  of  glaciers,  when  he  announced  the  following  facts, 
viz. :  '  That  ice  does  not  pass  abruptly  from  the  solid  to 
the  fluid  state  ;  that  it  begins  to  soften  at  a  temperature  of 
2°  Centigrade  below  its  thawing  point ;  that,  consequently, 
between  28°  4'  and  32°  of  Fahr.  ice  is  actually  passing 
.through  various  degrees  of  plasticity  within  narrower  lim- 
its, but  in  the  same  manner  that  wax,  for  example,  softens 
before  its  melts.'  "  The  "  softening"  here  referred  to  is 
the  "  friability  "  of  Sir  J.  Leslie,  and  what  I  have  called  a 
"  loosening  of  the  texture."  Let  us  suppose  the  Serpen- 
tine covered  by  a  sheet  of  pitch  so  smooth  and  hard  as  to 
enable  a  skater  to  glide  over  it ;  and  which  is  afterwards 
gradually  warmed  until  it  begins  to  bend  under  his  weight, 


334  ROTTEN  ICE   AND   SOFTENED   WAX. 

and  finally  lets  him  through.  A  comparison  of  this 
deportment  with  that  of  a  sheet  of  ice  under  the  same 
circumstances  enables  us  to  decide  whether  ice  "  passes 
through  various  degrees  of  plasticity  in  the  same  manner 
as  wax  S9ftens  before  it  melts."  M.  Person  concerned 
himself  solely  with  the  heat  absorbed,  and  no  doubt 
in  both  wax  and  ice  that  heat  is  expended  in  "  interior 
work."  In  the  one  case,  however,  the  body  is  so  consti- 
tuted that  the  absorbed  heat  is  expended  in  rendering  the 
substance  viscous ;  and  the  question  simply  is,  whether 
the  heat  absorbed  by  the  ice  gives  its  molecules  a  freedom 
of  play  which  would  entitle  it  also  to  be  called  viscous ; 
whether,  in  short,  "  rotten  ice  "  and  softened  wax  present 
the  same  physical  qualities  ? 


(20.) 

THERE  is  one  other  point  in  connection  with  the  viscous 
theory  which  claims  our  attention.  The  announcement  of 
that  theory  startled  scientific  men,  and  for  two  or  three 
years  after  its  first  publication  it  formed  the  subject  of 
keen  discusssion.  This  finally  subsided,  and  afterwards 
Professor  Forbes  drew  up  an  elaborate  paper,  which  was 
presented  in  three  parts  to  the  Royal  Society  in  1845  and 
1846,  and  subsequently  published  in  the  "  Philosophical 
Transactions." 

In  the  concluding  portion  of  Part  III.  Professor  Forbes 
states  and  answers  the  question,  "  How  far  a  glacier  is  to 
be  regarded  as  a  plastic  mass?"  in  these  words: — "Were 
a  glacier  composed  of  a  solid  crystalline  cake  of  ice, 
fitted  or  moulded  to  the  mountain  bed  which  it  occupies, 
like  a  lake  tranquilly  frozen,  it  would  seem  impossible 
to  admit  such  a  flexibility  or  yielding  of  parts  as  should 


CAPILLARY  HYPOTHESIS.  335 

permit  any  comparison  to  a  fluid  or  semifluid  body,  trans- 
mitting pressure  horizontally,  and  whose  parts  might 
change  their  mutual  positions  so  that  one  part  should  be 
pushed  out  whilst  another  remained  behind.  But  we 
know,  in  point  of  fact,  that  a  glacier  is  a  body  very  dif- 
ferently constituted.  It  is  clearly  proved  by  the  experi- 
ments of  Agassiz  and  others,  that  the  glacier  is  not  a  mass 
of  ice,  but  of  ice  and  water,  the  latter  percolating  freely 
through  the  crevices  of  the  former  to  all  depths  of  the  gla- 
cier ;  and  it  is  a  matter  of  ocular  demonstration  that  these 
crevices,  though  very  minute,  communicate  freely  with 
one  another  to  great  distances ;  the  water  with  which  they 
are  filled  communicates  force  also  to  great  distances,  and 
exercises  a  tremendous  hydrostatic  pressure  to  move  on- 
wards, in  the  direction  in  which  gravity  urges  it,  the  vast 
porous  mass  of  seemingly  rigid  ice  in  which  it  is  as  it 
were  bound  up." 

"  Now  the  water  in  the  crevices,"  continues  Professor 
Forbes,  "  does  not  constitute  the  glacier,  but  only  the 
principal  vehicle  of  the  force  which  acts  on  it,  and  the  slow 
irresistible  energy  with  which  the  icy  mass  moves  onwards 
from  hour  to  hour  with  a  continuous  march,  bespeaks  of 
itself  the  presence  of  a  fluid  pressure.  But  if  the  ice  were 
not  in  some  degree  ductile  or  plastic,  this  pressure  could 
never  produce  any  the  least  forward  motion  of  the  mass. 
The  pressure  in  the  capillaries  of  the  glacier  can  only  tend 
to  separate  one  particle  from  another,  and  thus  produce 
tensions  and  compressions  within  the  body  of  the  glacier 
itself,  which  yields,  owing  to  its  slightly  ductile  nature,  in 
the  direction  of  least  resistance,  retaining  its  continuity, 
or  recovering  it  by  reattachment  after  its  parts  have  suf- 
fered a  bruise,  according  to  the  violence  of  the  action  to 
which  it  has  been  exposed." 

I  will  not  pretend  to  say  that  I  fully  understand  this 
passage,  but,  taking  it  and  the  former  one  together,  I  think 
22 


836      TEMPERATURE  AT  CHAMOUNI ;  WINTER  1859. 


it  is  clear  that  the  water  which  is  supposed  to  gorge  the 
capillaries  of  the  glacier  is  assumed  to  be  essential  to  its 
motion.  Indeed,  an  extreme  degree  of  sensitiveness  has 
been  ascribed  to  the  glacier  as  regards  the  changes  of 
temperature  by  which  the  capillaries  are  affected.  In 
three  succeeding  days,  for  example,  Professor  Forbes 
found  the  diurnal  summer  motion  of  a  point  upon  the 
Mer  de  Glace  to  increase  from  15.2  to  17.5  inches  a 
day ;  a  result  which  he  says  he  is  "  persuaded  "to  be 
due  to  the  increasing  heat  of  the  weather  at  the  time. 
If,  then,  the  glacier  capillaries  can  be  gorged  so  quickly 
as  this  experiment  would  indicate,  it  is  fair  to  assume  that 
they  are  emptied  with  corresponding  speed  when  the  sup- 
ply is  cut  away. 

The  extraordinary  coldness  of  the  weather  previous  to 
the  Christmas  of  1859  is  in  the  recollection  of  everybody  : 
this  lowness  of  temperature  also  extended  to  the  Mer  de 
Glace  and  its  environs.  I  had  last  summer  left  with 
Auguste  Balmat  and  the  Abbe  Yueillet  thermometers 
with  which  observations  were  made  daily  during  the  cold 
weather  referred  to.  I  take  the  following  from  Balmat's 
register. 


Date. 

December  16 
17 

"         18 

"         19 

20 

"         21 


Minimum 
temperature 
Centigrade. 

—15° 
—20 


—13 
-201 


22    . 


Date. 

December  23 

«          24 

"          25 

"  26 

27 

28 

29 


Minimum 
temperature 
Centigrade. 


-6* 

—  2 
+  2 

—  3 


The  temperature  at  the  Montanvert  during  the  above 
period  may  be  assumed  as  generally  some  degrees  lower,  s( 
that,  for  a  considerable  period  previous  to»my  winter  obser- 
vations, the  portion  of  the  Mer  de  Glace  near  the  Montan- 
vert had  been  exposed  to  a  very  low  temperature.  I  reachet 


BALMAT'S  MEASUREMENTS.  337 

the  place  after  the  weather  had  become  warm,  but  during 
my  stay  there  the  maximum  temperature  did  not  exceed 
— 4^°  C.  Considering  therefore  the  long  .drain  to  which 
the  glacier  had  been  subjected  previous  to  the  29th  of 
December,  it  is  not  unreasonable  to  infer  that  the  capil- 
lary supply  assumed  by  Professor  Forbes  must  by  that 
time  have  been  exhausted.  Notwithstanding  this,  the 
motion  of  the  glacier  at  the  Montanvert  amounted  at  the 
md  of  December  to  half  its  maximum  summer  motion. 

The  observations  of  Balmat  which  have  been  published 
>y  Professor  Forbes  *  also  militate,  as  far  as  they  go, 
against  the  idea  of  proportionality  between  the  capillary 
upply  and  the  motion.     If  the  temperatures  recorded 
ipply  to  the  Mer  de  Glace  during  the  periods  of  observa- 
ion,  it  would  follow  that  from  the  19th  of  December, 
1846,  to  the  12th  of  April,  1847,  the  temperature  of  the 
air  was  constantly  under  zero  Centigrade,  and  hence,  dur- 
ng  this  time,  the  gorging  of  the  capillaries,  which  is  due 
;o  superficial  melting,  must  have  ceased.   Still,  throughout 
this  entire  period  of  depletion,  the  motion  of  the  glacier 
steadily  increased  from  twenty-four  inches  to  thirty-four 
and  a  half  inches  a  day.    What  has  been  here  said  of  the 
Montanvert,  and  of  the  points  lower  down  where  Balmat's 
measurements  were  made,  of  course  applies  with  greater 
brce  to  the  higher  portions  of  the  glacier,  which  are 
withdrawn  from  the  operation  of  superficial  melting  for  a 
onger  period,  and  which,  nevertheless,  if  I  understand 
Professor  Forbes  aright,  have  their  motion  least  affected 
n  winter.     He  records,  for  example,  an  observation  of 
Mr.  Bakewell's,  by  which  the  Glacier  des  Bossons  is  shown 
to  be  stationary  at  its  end,  while  its  upper  portions  are 
moving  at  the  rate  of  a  foot  a  day.     This  surely  indicates 
that,  at  those  places  where  the  glacier  is  longest  cut  off 
from  superficial  supply,  the  motion  is  least  reduced,  which 

*  "  Occ.  Pap./'  p.  224. 


338  BAKEWELL'S  OBSERVATIONS. 

would  be  a  most  strange  result  if  the  motion  depended, 
as  affirmed,  upon  the  gorging  of  the  capillaries. 

The  perusal  of  the  conclusion  of  Professor  Forbes's  last 
volume  shows  me  that  a  thought  similar  to  that  expressed 
above  occurred  to  Mr.  Bakewell  also.  Speaking  of  a  shal- 
low glacier  which  moved  when  the  alleged  temperature 
was  so  enormously  below  the  freezing  point  that  Professor 
Forbes  regards  it  as  unlikely  (in  which  I  agree  with  him) , 
Mr.  Bakewell  asks,  "  Is  it  possible  that  infiltrated  water 
can  have  any  action  whatever  under  such  circumstances  ? " 
The  reply  of  Professor  Forbes  contains  these  words :  — 
"  I  have  nowhere  affirmed  the  presence  of  liquid  water  to 
be  a  sine  qua  non  to  the  plastic  motion  of  glaciers."  This 
statement,  I  confess,  took  me  by  surprise,  which  was  not 
diminished  by  further  reading.  Speaking  of  the  influence 
of  temperature  on  the  motion  of  the  Mer  de  Glace,  Pro- 
fessor Forbes  says,  the  glacier  "  took  no  real  start  until 
the  frost  had  given  way,  and  the  tumultuous  course  of 
the  Arveiron  showed  that  its  veins  were  again  filled  with 
the  circulating  medium  to  which  the  glacier,  like  the  or- 
ganic frame,  ow«s  its  moving  energy."  *  And  again  :  — 
"  It  is  this  fragility  precisely  which,  yielding  to  the  hydro- 
static pressure  of  the  unfrozen  water  contained  in  the 
countless  capillaries  of  the  glacier,  produces  the  crushing 
action  which  shoves  the  ice  over  its  neighbour  particles.' 

After  the  perusal  of  the  foregoing  paragraphs  the  reader 
will  probably  be  less  interested  in  the  question  as  to 
whether  the  assumed  capillaries  exist  at  all  in  the  glacier. 
According  to  Mr.  Huxley's  observations,  they  do  not.f 
During  the  summer  of  1857  he  carefully  experimented 
with  coloured  liquids  on  the  Mer  de  Glace  and  its  tribu- 
taries, and  in  no  case  was  he  able  to  discover  these  fissures 
in  the  sound  unweathered  ice.  I  have  myself  seen  the  red 

*  Reprint  of  Memoirs  in  Phil.  Trans.,  "  Occ.  Pap.,"  p.  138. 
t  "Occ.  Pap.,"  p.  47. 


HUXLEY'S  OBSERVATIONS.  339 

liquid  resting  in  an  auger-hole,  where  it  had  lain  for  an 
hour  without  diffusing  itself  in  any  sensible  degree.  This 
cavity  intersected  both  the  white  ice  and  the  blue  veins 
of  the  glacier ;  and  Mr.  Huxley,  in  my  presence,  cut  away 
the  ice  until  the  walls  of  the  cavity  became  extremely  thin, 
still  no  trace  of  liquid  passed  through  them.  Experiments 
were  also  made  upon  the  higher  portions  of  the  Mer  de 
Glace,  and  also  on  the  Glacier  du  Ge*ant,  with  the  same 
result.  Thus  the  very  existence  of  these  capillaries  is 
rendered  so  questionable,  that  no  theory  of  glacier-motion 
which  invokes  their  aid  could  be  considered  satisfactory. 


340  STATEMENT  OF  THEORY. 

THOMSON'S  THEORY. 

(21.) 

IN  the  "  Transactions  "  of  the  Royal  Society  of  Edinburgh 
for  1849  is  published  a  very  interesting  paper  by  Prof.  James 
Thomson  of  Queen's  College,  Belfast,  wherein  he  deduces, 
as  a  consequence  of  a  principle  announced  by  the  French 
philosopher  Carnot,  that  water,  when  subjected  to  pressure, 
requires  a  greater  cold  to  freeze  it  than  when  the  pressure 
is  removed.  He  inferred  that  the  lowering  of  the  freezing 
point  for  every  atmosphere  of  pressure  amounted  to  .0075 
of  a  degree  Centigrade.  This  deduction  was  afterwards 
submitted  to  the  test  of  experiment  by  his  distinguished 
brother,  Prof.  Wm.  Thomson,  and  proved  correct.  On  the 
fact  thus  established  is  founded  Mr.  James  Thomson's  the- 
ory of  the  "  Plasticity  of  Ice  as  manifested  in  Glaciers." 

The  theory  is  this:  —  Certain  portions  of  the  glacier  are 
supposed  first  to  be  subjected  to  pressure.  This  pressure 
liquefies  the  ice,  the  water  thus  produced  being  squeezed 
through  the  glacier  in  the  direction  in  which  it  can  most 
easily  escape.  But  cold  has  been  evolved  by  the  act  of 
liquefaction,  and,  when  the  water  has  been  relieved  from 
the  pressure,  it  freezes  in  a  new  position.  The  pressure 
being  thus  abolished  at  the  place  where  it  was  first  applied, 
new  portions  of  the  ice  are  subjected  to  the  force ;  these 
in  their  turn  liquefy,  the  water  is  dispersed  as  before, 
and  re-frozen  in  some  other  place.  To  the  succession  of 
processes  here  assumed  Mr.  Thomson  ascribes  the  changes 
of  form  observed  in  glaciers. 

This  theory  was  first  communicated  to  the  Royal  Society 
through  the  author's  brother,  Prof.  William  Thomson,  and 
is  printed  in  the  "  Proceedings  "  of  the  Society  for  May, 
1857.  It  was  afterwards  communicated  to  the  British 


DIFFICULTIES   OF   THEORY.  341 

Association  in  Dublin,  in  whose  "  Reports  "  it  is  further 
published  ;  and  again  it  was  communicated  to  the  Belfast 
Literary  and  Philosophical  Society,  in  whose  "  Proceed- 
ings" it  also  finds  a  place. 

On  the  24th  of  November,  1859,  Mr.  James  Thomson 
communicated  to  the  Royal  Society,  through  his  brother, 
a  second  paper,  in  which  he  again  draws  attention  to  his 
theory.  He  offers  it  in  substitution  for  my  views  as  the 
best  argument  that  he  can  adduce  against  them ;  he  also 
controverts  the  explanations  of  regelation  propounded  by 
Prof.  James  D.  Forbes  and  Prof.  Faraday,  believing  that 
his  own  theory  explains  all  the  facts  so  well  as  to  leave 
room  for  no  other. 

But  the  passage  in  this  paper  which  demands  my  chief 
attention  is  the  following  :  —  "  Prof.  Tyndall  (writes  Mr. 
Thomson),  in  papers  and  lectures  subsequent  to  the  pub- 
lication of  this  theory,  appears  to  adopt  it  to  some  extent, 
and  to  endeavour  to  make  its  principles  co-operate  with 
the  views  he  had  previously  founded  on  Mr.  Faraday's  fact 
of  regelation."  I  may  say  that  Mr.  Thomson's  main 
thought  was  familiar  to  me  long  before  his  first  commu- 
nication on  the  plasticity  of  ice  appeared  ;  but  it  had  little 
influence  upon  my  convictions.  Were  the  above  passage 
correct,  I  should  deserve  censure  for  neglecting  to  express 
my  obligations  far  more  explicitly  than  I  have  hitherto 
done  ;  but  I  confess  that  even  now  I  do  not  understand 
the  essential  point  of  Mr.  Thomson's  theory,  —  that  is  to 
say,  its  application  to  the  phenomena  of  glacier  motion. 
Indeed,  it  was  the  obscurity  in  my  mind  in  connexion 
with  this  point,  and  the  hope  that  time  might  enable  me 
to  seize  more  clearly  upon  his  meaning,  which  prevented 
me  from  giving  that  prominence  to  the  theory  of  Mr. 
Thomson  which,  for  aught  I  know,  it  may  well  deserve. 
I  will  here  briefly  state  one  or  two  of  my  difficulties,  and 
shall  feel  very  grateful  to  have  them  removed. 


342  IMPROBABLE  DEDUCTION. 

Let  us  fix  our  attention  on  a  vertical  slice  of  ice  trans- 
verse to  the  glacier,  and  to  which  the  pressure  is  applied 
perpendicular  to  its  surfaces.  The  ice  liquefies,  and,  sup- 
posing the  means  of  escape  offered  to  the  compressed  water 
to  be  equal  all  round,  it  is  plain  that  there  will  be  as  great 
a  tendency  to  squeeze  the  water  upwards  as  downwards  ; 
for  the  mere  tendency  to  flow  down  by  its  own  gravity 
becomes,  in  comparison  to  the  forces  here  acting  on  the 
water,  a  vanishing  quantity.  But  the  fact  is,  that  the  ice 
above  the  slice  is  more  permeable  than  that  below  it ;  for, 
as  we  descend  a  glacier,  the  ice  becomes  more  compact. 
Hence  the  greater  part  of  the  dispersed  water  will  be  re- 
frozen  on  that  side  of  the  slice  which  is  turned  towards 
the  origin  of  the  glacier ;  and  the  consequence  is,  that, 
according  to  Mr.  Thomson's  principle,  the  glacier  ought 
to  move  up  hill  instead  of  down. 

I  would  invite  Mr.  Thomson  to  imagine  himself  and  me 
together  upon  the  ice,  desirous  of  examining  this  question 
in  a  philosophic  spirit ;  and  that  we  have  taken  our  places 
beside  a  stake  driven  into  the  ice,  and  descending  with  the 
glacier.  We  watch  the  ice  surrounding  the  stake,  and  find 
that  every  speck  of  dirt  upon  it  retains  its  position  ;  there 
is  no  liquefaction  of  the  ice  that  bears  the  dirt,  and  con- 
sequently it  rests  on  the  glacier  undisturbed.  After  twelve 
hours  we  find  the  stake  fifteen  inches  distant  from  its  first 
position  :  I  would  ask  Mr.  Thomson  how  did  it  get  there? 
Or  let  us  fix  our  attention  on  those  six  stakes  which  M. 
Agassiz  drove  into  the  glacier  of  the  Aar  in  1841,  and 
found  erect  in  1842  at  some  hundreds  of  feet  from  their 
first  position  :  — how  did  they  get  there  ?  How,  in  fine, 
does  the  end  of  a  glacier  become  its  end  ?  Has  it  been 
liquefied  and  re-frozen  ?  If  not,  it  must  have  been  pushed 
down  by  the  very  forces  which  Mr.  Thomson  invokes  to 
produce  his  liquefaction.  Both  the  liquefaction,  as  far  as 
it  exists,  and  the  motion,  are  products  of  the  same  cause. 


REQUISITE  PRESSURE  CALCULATED.  343 

111  short,  this  theory,  as  it  presents  itself  to  my  mind,  is 
so  powerless  to  account  for  the  simplest  fact  of  glacier- 
motion,  that  I  feel  disposed  to  continue  to  doubt  my  own 
competence  to  understand  it,  rather  than  ascribe  to  Mr. 
Thomson  an  hypothesis  apparently  so  irrelevant  to  the 
facts  which  it  professes  to  explain. 

Another  difficulty  is  the  following: — Mr.  Thomson  will 
have  seen  that  I  have  recorded  certain  winter  measure- 
ments made  on  the  Mer  de  Glace,  and  that  these  mea- 
surements show  not  only  that  the  ice  moves  at  that  period 
of  the  year,  but  that  it  exhibits  those  characteristics  of 
motion  from  which  its  plasticity  has  been  inferred  ;  the 
velocity  of  the  central  portions  of  the  glacier  being  in 
round  numbers  double  the  velocity  of  those  near  the 
sides.  Had  there  been  any  necessity  for  it,  this  ratio 
might  have  been  augmented  by  placing  the  side-stakes 
closer  to  the  walls  of  the  glacier.  Considering  the  ex- 
treme coldness  of  the  weather  which  preceded  these  mea- 
surements, it  is  a  moderate  estimate  to  set  down  the 
temperature  of  the  ice  in  which  my  stakes  were  fixed  at 
5°  Cent,  below  zero. 

Let  us  now  endeavour  to  estimate  the  pressure  existing 
at  the  portion  of  the  glacier  where  these  measurements 
were  made.  The  height  of  the  Montanvert  above  the  sea- 
level  is,  according  to  Prof.  Forbes,  6,300  feet ;  that  of  the 
Col  du  Ge'ant,  which  is  the  summit  of  the  principal  tribu- 
tary of  the  Mer  de  Glace,  is  11,146  feet :  deducting  the 
former  from  the  latter,  we  find  the  height  of  the  Col  du 
Gdant  above  the  Montanvert  to  be  4,846  feet. 

Now,  according  to  Mr.  Thomson's  theory  and  his  bro- 
ther's experiments,  the  melting  point  of  ice  is  lowered 
.0075  Centigrade  for  every  atmosphere  of  pressure ;  and 
one  atmosphere  being  equivalent  to  the  pressure  of  about 
thirty-three  feet  of  water,  we  shall  not  be  over  the  truth 
if  we  take  the  height  of  an  equivalent  column  of  glacier- 


344  ACTUAL  PRESSURE  INSUFFICIENT. 

ice,  of  a  compactness  the  mean  of  those  which  it  exhibits 
upon  the  Col  du  Ge'ant  and  at  the  Montanvert  respec- 
tively, at  forty  feet.  The  compactness  of  glacier-ice  is,  of 
course,  affected  by  the  air-bubbles  contained  within  it. 

If,  then,  the  pressure  of  forty  feet  of  ice  lower  the  melt- 
ing point  .0075  Centigrade,  it  follows  that  the  pressure  of 
a  column  4,846  feet  high  will  lower  it  nine-tenths  of  a  de- 
gree Centigrade.  Supposing,  then,  the  unimpeded  thrust 
of  the  whole  glacier,  from  the  Col  du  Geant  downwards, 
to  be  exerted  on  the  ice  at  the  Montanvert ;  or,  in  other 
words,  supposing  the  bed  of  the  glacier  to  be  absolutely 
smooth  and  every  trace  of  friction  abolished,  the  utmost 
the  pressure  thus  obtained  could  perform  would  be  to  lower 
the  melting  point  of  the  Montanvert  ice  by  the  quantity 
above  mentioned.  Taking  into  account  the  actual  state 
of  things,  the  friction  of  the  glacier  against  its  sides  and 
bed,  the  opposition  which  the  three  tributaries  encounter 
in  the  neck  of  the  valley  at  Tre*laporte,  the  resistance  en- 
countered in  the  sinuous  valley  through  which  it  passes ; 
and  finally,  bearing  in  mind  the  comparatively  short  length 
of  the  glacier  which  has  to  bear  the  thrust,  and  oppose 
the  latter  by  its  own  friction  merely,  —  I  think  it  will  ap- 
pear evident  that  the  ice  at  the  Montanvert  cannot  possi- 
bly have  its  melting  point  lowered  by  pressure  more  than 
a  small  fraction  of  a  degree. 

The  ice  in  which  my  stakes  were  fixed  being  — 5°  Cen- 
tigrade, according  to  Mr.  Thomson's  calculation  and  his 
brother's  experiments,  it  would  require  667  atmospheres 
of  pressure  to  liquefy  it ;  in  other  words,  it  would  require 
the  unimpeded  pressure  of  a  column  of  glacier-ice  26,680 
feet  high.  Did  Mont  Blanc  rise  to  two  and  a  half  times 
its  present  height  above  the  Montanvert,  and  were  the 
latter  place  connected  with  the  summit  of  the  mountain 
by  a  continuous  glacier  with  its  bed  absolutely  smooth, 
the  pressure  at  the  Montanvert  would  be  rather  under 


MEASUREMENTS  APPLY  TO  SURFACE.     345 

that  necessary  to  liquefy  the  ice  on  which  my  winter  ob- 
servations were  made. 

If  it  be  urged  that,  though  the  temperature  near  the 
surface  may  be  several  degrees  below  the  freezing  point, 
the  great  body  of  the  glacier  does  not  share  this  tempera- 
ture, but  is,  in  all  probability,  near  to  32°,  my  reply  is 
simple.  I  did  not  measure  the  motion  of  the  ice  in  the 
body  of  the  glacier  ;  nobody  ever  did ;  my  measurements 
refer  to  the  ice  at  and  near  the  surface,  and  it  is  this  ice 
which  showed  the  plastic  deportment  which  the  measure- 
ments reveal. 

Such,  then,  are  some  of  the  considerations  which  pre- 
vent me  from  accepting  the  theory  of  Mr.  Thomson,  and  I 
trust  they  will  acquit  me  of  all  desire  to  make  his  theory 
co-operate  with  my  views.  I  am,  however,  far  from  con- 
sidering his  deduction  the  less  important  because  of  its 
failing  to  account  for  the  phenomena  of  glacier  motion. 


346 


POSSIBLE   MOULDING  OF  ICE. 


THE    PRESSURE-THEORY    OF     GLACIER-MOTION. 

(22.) 

BROADLY  considered,  two  classes  of  facts  are  presented  to 
the  glacier-observer ;  the  one  suggestive  of  viscosity,  and 
the  other  of  the  reverse.  The  former  are  seen  where  pres- 
sure comes  into  play,  the  latter  where  tension  is  operative. 
By  pressure  ice  can  be  moulded  to  any  shape,  while  the 
same  ice  snaps  sharply  asunder  if  subjected  to  tension. 
Were  the  result  worth  the  labour,  ice  might  be  moulded 
into  vases,  statuettes,  bent  into  spiral  bars,  and,  I  doubt 
not,  by  the  proper  application  of  pressure,  a  rope  of  ice 
might  be  formed  and  coiled  into  a  knot.  But  not  one  of 
these  experiments,  though  they  might  be  a  thousand-fold 
more  striking  than  any  ever  made  upon  a  glacier,  would 
in  the  least  demonstrate  that  ice  is  really  a  viscous  body. 

I  have  here  stated  what  I  believe  to  be  feasible.  Let 
me  now  refer  to  the  experiments  which  have  been  actually 


Fig.  30. 

made  in  illustration  of  this  point.  Two  pieces  of  seasoned 
box-wood  had  corresponding  cavities  hollowed  in  them,  so 
that,  when  one  was  placed  upon  the  other,  a  lenticular 


ACTUAL  MOULDING  OF  ICE. 


347 


space  was  enclosed.  A  and  B,  Fig.  30,  represent  the 
pieces  of  box-wood  with  the  cavities  in  plan :  c  represents 
their  section  when  they  are  placed  upon  each  other. 

A  sphere  of  ice  rather  more  than  sufficient  to  fill  the 
lenticular  space  was  placed  between  the  pieces  of  wood 
and  subjected  to  the  action  of  a  small  hydraulic  press. 
The  ice  was  crushed,  but  the  crushed  fragments  soon  re- 
attached  themselves,  and,  in  a  few  seconds,  a  lens  of  com- 
pact ice  was  taken  from  the  mould. 

This  lens  was  placed  in  a  cylindrical  cavity  hollowed  out 
in  another  piece  of  box- wood,  and  represented  at  c,  Fig.  31 ; 
and  a  flat  piece  of  the  wood  was  placed 
over  the  lens  as  a  cover,  as  at  D.  On  sub- 
jecting the  whole  to  pressure,  the  lens 
broke,  as  the  sphere  had  done,  but  the 
crushed  mass  soon  re-established  its  contin- 
uity, and  in  less  than  half  a  minute  a  com- 
pact cake  of  ice  was  taken  from  the  mould. 

In  the  following  experiment,  the  ice  was 
subjected  to  a  still  severer  test :  —  A  hemi- 
spherical cavity  was  formed  in  one  block  of 
box- wood,  and  upon  a  second  block  a  hemi- 
spherical protuberance  was  turned,  smaller  than  the  cavity, 
so  that,  when  the  latter  was  placed  in  the  former,  a  space 
of  a  quarter  of  an  inch  existed  between  both.  Fig.  32 
represents  a  section  of  the  two  ^ 
pieces  of  box- wood ;  the  brass  pins 
ft,  b,  fixed  in  the  slab  G  H,  and 
entering  suitable  apertures  in  the 
mould  i  K,  being  intended  to 
keep  the  two  surfaces  concentric. 
A  lump  of  ice  being  placed  in 


Fig.  si. 


Fig.  32. 


the  cavity,  the  protuberance  was  brought  down  upon  it, 
and  the  mould  subjected  to  hydraulic  pressure  :  after  a 
short  interval  the  ice  was  taken  from  the  mould  as  a 


j 


348  ICE  MOULDED   TO   CUPS  AND  RINGS. 

smooth  compact  cup,  its  crushed  particles  having  reunited, 
and  established  their  continuity. 

To  make  these  results  more  applicable  to  the  bending  of 
glacier-ice,  the  following  experiments  were  made : — A  block 
of  box-wood,  M,  Fig.  33,  4  inches  long,  3  wide,  and  3  deep, 
had  its  upper  surface  slightly  curved 
and  a  groove  an  inch  wide,  and  about 
an  inch  deep,  worked  into  it.  A  corre- 
sponding plate  was  prepared,  having 
its  under  surface  part  of  a  convex  cyl- 
inder, of  the  same  curvature  as  the 
concave  surface  of  the  former  piece. 
When  the  one  slab  was  placed  upon 
the  other,  they  presented  the  appear- 
ance represented  in  section  at  N.  A 
Fj  straight  prism  of  ice  4  inches  long,  an 

inch  wide,  and  a  little  more  than  an 
inch  in  depth,  was  placed  in  the  groove ;  the  upper  slab 
was  placed  upon  it,  and  the  whole  was  subjected  to  the 
hydraulic  press.  The  prism  broke,  but,  the  quantity  of  ice 
being  rather  more  than  sufficient  to  fill  the  groove,  the 
pressure  soon  brought  the  fragments  together  and  re- 
established the  continuity  of  the  ice.  After  a  few  seconds 
it  was  taken  from  the  mould  a  bent  bar  of  ice.  This  bar 
was  afterwards  passed  through  three  other  moulds  of 
gradually  augmenting  curvature,  and  was  taken  from 
the  last  of  them  a  semi-ring'  of  compact  ice. 

The  ice,  in  changing  its  form  from  that  of  one  mould  to 
that  of  another,  was  in  every  instance  broken  and  crushed 
by  the  pressure  ;  but  suppose  that  instead  of  three  moulds 
three  thousand  had  been  used ;  or,  better  still,  suppose  the 
curvature  of  a  single  mould  to  change  by  extremely  slow 
degrees ;  the  ice  would  then  so  gradually  change  its  form 
that  no  rude  rupture  would  be  apparent.  Practically  the 
ice  would  behave  as  a  plastic  substance ;  and  indeed 


.  SOFTNESS   OF  ICE   DEFINED.  849 

this  plasticity  has  been  contended  for  by  M.  Agassiz,  in 
opposition  to  the  idea  of  viscosity.  As  already  stated,  the 
ice,  bruised,  and  flattened,  and  bent  in  the  above  experi- 
ments, was  incapable  of  being  sensibly  stretched ;  it  was 
plastic  to  pressure,  but  not  to  tension. 

A  quantity  of  water  was  always  squeezed  out  of  the 
crushed  ice  in  the  above  experiments,  and  the  bruised 
fragments  were  intermixed  with  this  and  with 'air.  Minute 
quantities  of  both  remained  in  the  moulded  ice,  and  thus 
rendered  it  in  some  degree  turbid.  Its  character,  how- 
ever, as  to  continuity,  may  be  inferred  from  the  fact  that 
the  ice-cup,  moulded  as  described,  held  water  without  the 
slightest  visible  leakage. 

Ice  at  32°  may,  as  already  stated,  be  crushed  with 
extreme  facility,  and  glacier-ice  with  still  more  readiness 
than  lake-ice :  it  may  also  be  scraped  with  a  knife  with 
even  greater  facility  than  some  kinds  of  chalk.     In  com- 
parison with  ice  at  100°  below  the  freezing  point,  it  might 
be  popularly  called  soft.     But  its  softness  is  not  that  of 
paste,  or  wax,  or  treacle,  or  lava,  or  honey,  or  tar.   It  is  the 
softness  of  calcareous  spar  in  comparison  with  that  of  rock- 
|  crystal ;  and  although  the  latter  is  incomparably  harder 
than  the  former,  I  think  it  will  be  conceded  that  the  term 
viscous  would  be  equally  inapplicable  to  both.    My  object 
!  here  is  clearly  to  define  terms,  and  not  permit  physical 
i  error  to  lurk  beneath  them.    How  far  this  ice,  with  a  soft- 
ness thus  defined,  when  subjected  to  the  gradual  pressures 
exerted  in  a  glacier,  is  bruised  and  broken,  and  how  far  the 
motion  of  its  parts  may  approach  to  that  of  a  truly  viscous 
body  under  pressure,  I  do  not  know.     The  critical  point 
here  is,  that  the  ice  changes  its  form,  and  preserves  its 
continuity,  during  its  motion,  in  virtue  of  external  force. 
|  It  remains  continuous  whilst  it  moves,  because  its  par- 
i  tides  are  kept  in  juxtaposition  by  pressure,  and  when 
!  this  external  prop  is  removed,  and  the  ice,  subjected  to 


350  PRESSURE  AND   TENSION. 

tension,  has  to  depend  solely  upon  the  mobility  of  its  own 
particles  to  preserve  its  continuity,  the  analogy  with  a 
viscous  body  instantly  breaks  down.* 

*  "  Imagine/'  writes  Professor  Forbes,  "  a  long  narrow  trough  or  canal, 
stopped  at  both  ends  and  filled  to  a  considerable  depth  with  treacle,  honey, 
tar,  or  any  such  viscous  fluid.  Imagine  one  end  of  the  trough  to  give  way. 
the  bottom  still  remaining  horizontal :  if  the  friction  of  the  fluid  against  the 
bottom  be  greater  than  the  friction  against  its  own  particles,  the  upper 
strata  will  roll  over  the  lower  ones,  and  protrude  in  a  convex  slope,  which 
will  be  propagated  backwards  towards  the  other  or  closed  end  of  the 
trough.  Had  the  matter  been  quite  fluid  the  whole  would  have  run  out, 
and  spread  itself  on  a  level :  as  it  is,  it  assumes  precisely  the  conditions 
which  we  suppose  to  exist  in  a  glacier."  This  is  perfectly  definite,  and 
my  equally  definite  opinion  is  that  no  glacier  ever  exhibited  the  mechanical 
effects  implied  by  this  experiment. 


FARADAY'S   FIRST  EXPERIMENT.  351 

REGELATION. 

(23.) 

I  WAS  led  to  the  foregoing  results  by  reflecting  on  an 
experiment  performed  by  Mr.  Faraday,  at  a  Friday  even- 
ing meeting  of  the  Royal  Institution,  on  the  7th  of  June, 
1850,  and  described  in  the  "  Athenaeum  "  and  "  Literary 
Gazette  "  for  the  same  month.  Mr.  Faraday  then  showed 
that  when  two  pieces  of  ice,  with  moistened  surfaces,  were 
placed  in  contact,  they  became  cemented  together  by  the 
freezing  of  the  film  of  water  between  them,  while,  when 
the  ice  was  below  32°  Fahr.,  and  therefore  dry,  no  effect 
of  the  kind  could  be  produced.  The  freezing  was  also 
found  to  take  place  under  water ;  and  indeed  it  occurs 
even  when  the  water  in  which  the  ice  is  plunged  is  as  hot 
as  the  hand  can  bear. 

A  generalization  from  this  interesting  fact  led  me  to 
conclude  that  a  bruised  mass  of  ice,  if  closely  confined, 
must  re-cement  itself  when  its  particles  are  brought  into 
contact  by  pressure  ;  in  fact,  the  whole  of  the  experi- 
ments above  recorded  immediately  suggested  themselves 
to  my  mind  as  natural  deductions  from  the  principle  es- 
tablished by  Faraday.  A  rough  preliminary  experiment 
assured  me  that  the  deductions  would  stand  testing ;  and 
the  construction  of  the  box-wood  moulds  was  the  conse- 
quence. We  could  doubtless  mould  many  solid  substances 
to  any  extent  by  suitable  pressure,  breaking  the  attach- 
ment of  their  particles,  and  re-establishing  a  certain  con- 
tinuity by  the  mere  force  of  cohesion.  With  such  sub- 
stances, to  which  we  should  never  think  of  applying  the 
term  viscous,  we  might  also  imitate  the  changes  of  form  to 
which  glaciers  are  subject :  but,  superadded  to  the  mere 
cohesion  which  here  comes  into  play,  we  have  in  the  case 
23 


352  RECENT   EXPERIMENTS   OF  FARADAY. 

of  ice,  the  actual  regelation  of  the  several  surfaces,  and 
consequently  a  more  perfect  solid.  In  the  Introduction  to 
this  book  I  have  referred  to  the  production  of  slaty  cleav- 
age by  pressure  ;  and  at  a  future  page  I  hope  to  show  that 
the  lamination  of  the  ice  glaciers  is  due  to  the  same  cause  ; 
but,  as  justly  observed  by  Mr.  John  Ball,  there  is  no  ten- 
dency to  cleave  in  the  sound  ice  of  glaciers ;  in  fact,  this 
tendency  is  obliterated  by  the  perfect  regelation  of  the 
severed  surfaces. 

Mr.  Faraday  has  recently  placed  pieces  of  ice,  in  water, 
under  the  strain  of  forces  tending  to  pull  them  apart. 
When  two  such  pieces  touch  at  a  single  point  they  adhere 
and  move  together  as  a  rigid  piece ;  but  a  little  lateral 
force  carefully  applied  breaks  up  this  union  with  a  crack- 
ling noise,  and  a  new  adhesion  occurs  which  holds  the 
pieces  together  in  opposition  to  the  force  which  tends  to 
divide  them.  Mr.  James  Thomson  had  referred  regela- 
tion to  the  cold  produced  by  the  liquefaction  of  the  pressed 
ice  ;  but  in  the  above  experiment  all  pressure  is  not  only 
taken  away,  but  is  replaced  by  tension.  Mr.  Thomson 
also  conceives  that,  when  pieces  of  ice  are  simply  placed 
together  without  intentional  pressure,  the  capillary  attrac- 
tion brings  the  pressure  of  the  atmosphere  into  play ;  but 
Mr.  Faraday  finds  that  regelation  takes  place  in  vacua.  A 
true  viscidity  on  the  part  of  ice  Mr.  Faraday  never  has 
observed,  and  he  considers  that  his  recent  experiments 
support  the  view  originally  propounded  by  himself,  name- 
ly, that  a  particle  of  water  on  the  surface  of  ice  becomes 
solid  when  placed  between  two  surfaces,  because  of  the  in- 
creased influence  due  to  their  joint  action. 


HOW  CRYSTALS  ARE  "NURSED."  353 


CRYSTALLIZATION    AND    INTERNAL    LIQUE- 
FACTION. 

(24.) 

IN  the  Introduction  to  this  book  I  have  briefly  referred 
to  the  force  of  crystallization.  To  permit  this  force  to  ex- 
ercise its  full  influence,  it  must  have  free  and  unimpeded 
action  ;  a  crystal,  for  instance,  to  be  properly  built,  ought 
to  be  suspended  in  the  middle  of  the  crystallizing  solu- 
tion, so  that  the  little  architects  can  work  all  round  it ; 
or  if  placed  upon  the  bottom  of  a  vessel,  it  ought  to  be 
requently  turned,  so  that  all  its  facets  may  be  succes- 
sively subjected  to  the  building  process.  In  this  way 
crystals  can  be  nursed  to  an  enormous  size.  But  where 
>ther  forces  mingle  with  that  of  crystallization,  this  har- 
noiiy  of  action  is  destroyed  ;  the  figures,  for  example,  that 
we  see  upon  a  glass  window,  on  a  frosty  morning,  are  due 
to  an  action  compounded  of  the  pure  crystalline  force  and 
cohesion  of  the  liquid  to  the  window-pane.  A  more 
regular  effect  is  obtained  when  the  freezing  particles  are 
>uspended  in  still  air,  and  here  they  build  themselves  into 
jhose  wonderful  figures  which  Dr.  Scoresby  has  observed 
n  the  Polar  Regions,  Mr.  Glaisher  at  Greenwich,  and  I 
myself  on  the  summit  of  Monte  Rosa  and  elsewhere. 

Not  only  however  in  air,  but  in  water  also,  figures  of 

eat  beauty  are  sometimes  formed.  Harrison's  excellent 
uacliine  for  the  production  of  artificial  ice  is,  I  suppose, 
low  well  known  ;  the  freezing  being  effected  by  carrying 
)rine,  which  had  been  cooled  by  the  evaporation  of  ether, 
:ound  a  series  of  flat  tin  vessels  containing  water.  The 
atter  gradually  freezes,  and,  on  watching  those  vessels 

ile  the  action  was  proceeding  very  slowly,  I  have  seen 
ittle  six-rayed  stars  of  thin  ice  forming,  and  rising  to  the 


854  DISSECTION  OF  ICE   BY   SUNBEAM. 

surface  of  the  liquid.  I  believe  the  fact  was  never  before 
observed,  but  it  would  be  interesting  to  follow  it  up,  and 
to  develop  experimentally  this  most  interesting  case  of 
crystallization. 

The  surface  of  a  freezing  lake  presents  to  the  eye  of 
the  observer  nothing  which  could  lead  him  to  suppose  that 
a  similar  molecular  architecture  is  going  on  there.  Still 
the  particles  are  undoubtedly  related  to  each  other  in  this 
way  ;  they  are  arranged  together  on  this  starry  type.  And 
not  only  is  this  the  case  at  the  surface,  but  the  largest 
blocks  of  ice  which  reach  us  from  Norway  and  the  Wen- 
ham  Lake  are  wholly  built  up  in  this  way.  We  can  re- 
veal the  internal  constitution  of  these  masses  by  a  reverse 
process  to  that  which  formed  them ;  we  can  send  an  agent 
into  the  interior  of  a  mass  of  ice  which  shall  take  down 
the  atoms  which  the  crystallizing  forces  had  set  up. 
This  agent  is  a  solar  beam  ;  with  which  it  first  occurred 
to  me  to  make  this  simple  experiment  in  the  autumn  of 
1857.  I  placed  a  large  converging  lens  in  the  sunbeams 
passing  through  a  room,  and  observed  the  place  where 
the  rays  were  brought  to  a  focus  behind  the  lens  ;  then, 
shading  the  lens,  I  placed  a  clear  cube  of  ice  so  that  the 
point  of  convergence  of  the  rays  might  fall  within  it.  On 
removing  the  screen  from  the  lens,  a  cone  of  sunlight 
went  through  the  cube,  and  along  the  course  of  the  cone 
the  ice  became  studded  with  lustrous  spots,  evidently 
formed  by  the  beam,  as  if  minute  reflectors  had  been  sud- 
denly established  within  the  mass,  from  which  the  light 
flashed  when  it  met  them.  On  examining  the  cube  after- 
wards I  found  that  each  of  these  spots  was  surrounded  by  a 
liquid  flower  of  six  petals  ;  such  flowers  were  distributed 
in  hundreds  through  the  ice,  being  usually  clear  and  de- 
tached from  each  other,  but  sometimes  crowded  together 
into  liquid  bouquets,  through  which,  however,  the  six- 
starred  element  could  be  plainly  traced.  At  first  the  edges 


LIQUID  FLOWERS  IN  ICE. 


855 


of  the  leaves  were  unbroken  curves,  but  when  the  flowers  ex- 
panded under  a  long-continued  action,  the  edges  became 
serrated.  When  the  ice  was  held  at  a  suitable  angle  to  the 
solar  beams,  these  liquid  blossoms,  with  their  central  spots 
shining  more  intensely  than  burnished  silver,  presented 
an  exhibition  of  beauty  not  easily  described.  I  have  given 
a  sketch  of  their  appearance  in  Fig.  34. 


Fig.  34. 

I  have  here  to  direct  attention  to  an  extremely  curious 
fact.  On  sending  the  sunbeam  through  the  transparent 
ice,  I  often  noticed  that  the  appearance  of  the  lustrous 
spots  was  accompanied  by  an  audible  clink,  as  if  the  ice 
were  ruptured  inwardly.  But  there  is  no  ground  for 
assuming  such  rupture,  and  on  the  closest  examination 
no  flaw  is  exhibited  by  the  ice.  What  then  can  be  the 
cause  of  the  noise  ?  I  believe  the  following  considerations 
will  answer  the  question  :  — 

Water  always  holds  a  quantity  of  air  in  solution,  the 
diffusion  of  which  through  the  liquid,  as  proved  by  M. 
Donny,  has  an  immense  effect  in  weakening  the  cohesion 
of  its  particles ;  recent  experiments  of  my  own  show  that 
this  is  also  the  case  in  an  eminent  degree  with  many 
volatile  liquids.  M.  Donny  has  proved  that,  if  water  be 
thoroughly  purged  of  its  air,  along  glass  tube  filled  with 


356      WATER  DEPRIVED   OF   AIR   SNAPS   ASUNDER. 

this  liquid  may  be  inverted,  while  the  tenacity  with  which 
the  water  clings  to  the  tube,  and  with  which  its  particles 
cling  to  each  other,  is  so  great  that  it  will  remain  securely 
suspended,  though  no  external  hindrance  be  offered  to  its* 
descent.  Owing  to  the  same  cause,  water  deprived  of  its 
air  will  not  boil  at  212°  Fahr.,  and  may  be  raised  to  a  tem- 
perature of  nearly  300°  without  boiling  ;  but  when  this 
occurs  the  particles  break  their  cohesion  suddenly,  and 
ebullition  is  converted  into  explosion. 

Now,  when  ice  is  formed,  every  trace  of  the  air  which 
the  water  contained  is  squeezed  out  of  it ;  the  particles  in 
crystallizing  reject  all  extraneous  matter,  so  that  in  ice  we 
have  a  substance  quite  free  from  the  air,  which  is  never 
absent  in  the  case  of  water ;  it  therefore  follows  that  if  we 
could  preserve  the  water  derived  from  the  melting  of  ice 
from  contact  with  the  atmosphere,  we  should  have  a  liquid 
eminently  calculated  to  show  the  effects  described  by  M. 
Doiiny.  Mr.  Faraday  has  proved  by  actual  experiment 
that  this  is  the  case. 

Let  us  apply  these  facts  to  the  explanation  of  the  clink 
heard  in  my  experiments.  On  sending  a  sunbeam  through 
ice,  liquid  cavities  are  suddenly  formed  at  various  points 
within  the  mass,  and  these  cavities  are  completely  cut  off 
from  atmospheric  contact.  But  the  water  formed  by  the 
melting  ice  is  less  in  volume  than  the  ice  which  produces 
it ;  the  water  of  a  cavity  is  not  able  to  fill  it,  hence  a 
vacuous  space  must  be  formed  in  the  cell.  I  have  no 
doubt  that,  for  a  time,  the  strong  cohesion  between  the 
walls  of  the  cell  and  the  drop  within  it  augments  the 
volume  of  the  latter  a  little,  so  as  to  compel  it  to  fill  the 
cell ;  but  as  the  quantity  of  liquid  becomes  greater  the 
shrinking  force  augments,  until  finally  the  particles  snap 
asunder  like  a  broken  spring.  At  the  same  moment  a 
lustrous  spot  appears,  which  is  a  vacuum,  and  simul- 
taneously with  the  appearance  of  this  vacuum  the  clink 


FIGURES  IN  ICE;   VACUOUS   SPOTS.  357 

was  always  heard.  Multitudes  of  such  little  explosions 
must  be  heard  upon  a  glacier  when  the  strong  summer 
sun  shines  upon  it,  the  aggregate  of  which  must,  I  think, 
contribute  to  produce  the  "  crepitation "  noticed  by  M, 
Agassiz,  and  to  which  I  have  already  referred. 

In  Plate  VI.  of  the  Atlas  which  accompanies  the  "  Sys- 
teme  Glaciaire"  of  M.  Agassiz,  I  notice  drawings  of  figures 
like  those  I  have  described,  which  he  has  observed  in  glacier- 
ice,  and  which  were  doubtless  produced  by  direct  solar  radi- 
ation. I  have  often  myself  observed  figures  of  exquisite 
beauty  formed  in  the  ice  on  the  surface  of  glacier-pools  by 
the  morning  sun.  In  some  cases  the  spaces  between  the 
leaves  of  the  liquid  flowers  melt  partially  away,  and  leave 
the  central  spot  surrounded  by  a  crimped  border ;  some- 
times these  spaces  wholly  disappear,  and  the  entire  space 
bounded  by  the  lines  drawn  from  point  to  point  of  the  leaves 
becomes  liquid,  thus  forming  perfect  hexagons.  The 
crimped  borders  exhibit  different  degrees  of  serration,  from 
the  full  leaves  themselves  to  a  gentle  undulating  line, 
which  latter  sometimes  merges  into  a  perfect  circle.  In  the 
ice  of  glaciers,  I  have  seen  the  internal  liquefaction  ramify 
itself  like  sprigs  of  myrtle ;  in  the  same  ice,  and  particu- 
larly towards  the  extremities  of  the  glacier,  disks  innu- 
merable are  also  formed,  consisting  of  flat,  round  liquid 
spaces,  a  bright  spot  being  usually  associated  with  each. 
These  spots  have  been  hitherto  mistaken  for  air-bubbles ; 
but  both  they  and  the  lustrous  disks  at  the  centres  of  the 
flowers  are  vacuous.  I  proved  them  to  be  so  by  plunging 
the  ice  containing  them  into  hot  water,  and  watching 
what  occurred  when  the  walls  of  the  cells  were  dissolved, 
and  a  liquid  connexion  established  between  them  and  the 
atmosphere.  In  all  cases  they  totally  collapsed,  and  no 
trace  of  air  rose  to  the  surface  of  the  warm  water. 

No  matter  in  what  direction  a  solar  beam  is  sent  through 
lake-ice,  the  liquid  flowers  are  all  formed  parallel  to  the 


358  CONSTITUTION  OF  GLACIER  ICE. 

surface  of  freezing.  The  beam  may  be  sent  parallel,  perpen- 
dicular, or  oblique  to  this  surface  ;  the  flowers  are  always 
formed  in  the  same  planes.  Every  line  perpendicular  to 
the  surface  of  a  frozen  lake  is  in  fact  an  axis  of  symmetry, 
round  which  the  molecules  so  arrange  themselves,  that, 
when  taken  down  by  the  delicate  fingers  of  the  sunbeam, 
the  six-leaved  liquid  flowers  are  the  result. 

In  the  ice  of  glaciers  we  have  no  definite  planes  of 
freezing.  It  is  first  snow,  which  has  been  disturbed  by 
winds  while  falling,  and  whirled  and  tossed  about  by  the 
same  agency  after  it  has  fallen,  being  often  melted,  satu- 
rated with  its  own  water,  and  refrozen  ;  it  is  cast  in  shat- 
tered fragments  down  cascades,  and  reconsolidated  by 
pressure  at  the  bottom.  In  ice  so  formed  and  subjected 
to  such  mutations,  definite  planes  of  freezing  are,  of 
course,  out  of  the  question. 

The  flat,  round  disks  and  vacuous  spots  to  which  I  have 
referred  come  here  to  our  aid,  and  furnish  us  with  an  en- 
tirely new  means  of  analysing  the  internal  constitution  of  a 
glacier.  When  we  examine  a  mass  of  glacier-ice  which  con- 
tains these  disks,  we  find  them  lying  in  all  imaginable 
planes  ;  not  confusedly,  however,  —  closer  examination 
shows  us  that  the  disks  are  arranged  in  groups,  the  mem- 
bers of  each  group  being  parallel  to  a  common  plane,  but 
the  parallelism  ceases  when  different  groups  are  compared. 
The  effect  is  exactly  what  would  be  observed,  supposing  or- 
dinary lake-ice  to  be  broken  up,  shaken  together,  and  the 
confused  fragments  regelated  to  a  compact  continuous 
mass.  In  such  a  jumble  the  original  planes  of  freezing 
would  lie  in  various  directions ;  but  no  matter  how  com- 
pact or  how  transparent  ice  thus  constituted  might  appear, 
a  solar  beam  would  at  once  reveal  its  internal  constitution 
by  developing  the  flowers  parallel  to  the  planes  of  freezing 
of  the  respective  fragments.  A  sunbeam  sent  through  gla- 
cier-ice always  reveals  the  flowers  in  the  planes  of  the 


VACUOUS  CELLS  MISTAKEN  FOR  AIR-CELLS.     859 

disks,  so  that  the  latter  alone  at  once  informs  us  of  its 
crystalline  constitution. 

Hitherto,  as  I  have  said,  these  disks  have  heen  mistaken 
for  bubbles  containing  air,  and  their  flattening  has  been 
ascribed  to  the  pressure  to  which  they  have  been  sub- 
jected. M.  Agassiz  thus  refers  to  them:  —  "The  air- 
bubbles  undergo  no  less  curious  modifications.  In  the 
neighbourhood  of  the  neve,  where  they  are  most  nume- 
rous, those  which  one  sees  on  the  surface  are  all  spherical 
or  ovoid,  but  by  degrees  they  begin  to  be  flattened,  and 
near  the  end  of  the  glacier  there  are  some  that  are  so  flat 
that  they  might  be  taken  for  fissures  when  seen  in  profile. 
The  drawing  represents  a  piece  of  ice  detached  from  the 
gallery  of  infiltration.  All  the  bubbles  are  greatly  flat- 
tened. But  what  is  most  extraordinary  is,  that,  far  from 
being  uniform,  the  flattening  is  different  in  each  frag- 
ment ;  so  that  the  bubbles,  according  to  the  face  which 
they  offer,  appear  either  very  broad  or  very  thin."  This 
description  of  glacier-ice  is  correct :  it  agrees  with  the 
statements  of  all  other  observers.  But  there  are  two  as- 
sumptions in  the  description  which  must  henceforth  be 
given  up  ;  first,  the  bubbles  seen  like  fissures  in  profile 
are  not  air-bubbles  at  all,  but  vacuous  spots,  which  the 
very  constitution  of  ice  renders  a  necessary  concomitant 
of  its  inward  melting  ;  secondly,  the  assumption  that  the 
bubbles  have  been  flattened  by  pressure  must  be  aban- 
doned ;  for  they  are  found,  and  may  be  developed  at  will, 
in  lake-ice  on  which  no  pressure  has  been  exerted. 

But  these  remarks  dispose  only  of  a  certain  class  of 
cells  contained  in  glacier-ice.  Besides  the  liquid  disks 
and  vacuous  spots,  there  are  innumerable  true  bubbles 
entangled  in  the  mass.  These  have  also  been  observed 
and  described  by  M.  Agassiz  ;  and  Mr.  Huxley  has  also 
given  us  an  accurate  account  of  them.  M.  Agassiz  fre- 
quently found  air  and  water  associated  in  the  same  cell. 


360  CELLS  OF  AIR  AND   WATER. 

Mr.  Huxley  found  no  exception  to  the  rule :  in  each  case 
the  bubble  of  air  was  enclosed  in  a  cell  which  was  also 
partially  filled  with  water.  He  supposes  that  the  water 
may  be  tha.t  of  the  originally-melted  snow  which  has  been 
carried  down  from  the  neve  unfrozen.  This  hypothesis 
is  worthy  of  a  great  deal  more  consideration  than  I  have 
had  time  to  give  to  it,  and  I  state  it  here  in  the  hope  that 
it  will  be  duly  examined. 

My  own  experience  of  these  associated  air  and  water 
cells  is  derived  almost  exclusively  from  lake-ice,  in  which 
I  have  often  observed  them  in  considerable  numbers.  In 
examining  whether  the  liquid  contents  had  ever  been 
frozen  or  not,  I  was  guided  by  the  following  considera- 
tions. If  the  air  be  that  originally  entangled  in  the  solid, 
it  will  have  the  ordinary  atmospheric  density  at  least ; 
but  if  it  be  due  to  the  melting  of  the  walls  of  the  cell, 
then  the  water  so  formed  being  only  eight-ninths  of  that 
of  the  ice  which  produced  it,  the  air  of  the  bubble  must 
be  rarefied.  I  suppose  I  have  made  a  hundred  different 
experiments  upon  these  bubbles  to  determine  whether  the 
air  was  rarefied  or  not,  and  in  every  case  found  it  so. 
Ice  containing  the  bubbles  was  immersed  in  warm  water, 
and  always,  when  the  rigid  envelope  surrounding  a  bub- 
ble was  melted  away,  the  air  suddenly  collapsed  to  a 
fraction  of  its  original  dimensions.  I  think  I  may  safely 
affirm  that,  in  some  cases,  the  collapse  reduced  the 
bubbles  to  the  thousandth  part  of  their  original  volume. 
From  these  experiments  I  should  undoubtedly  infer,  that 
in  lake-ice  at  least,  the  liquid  of  the  cells  is  produced  by 
the  melting  of  the  ice  surrounding  the  bubbles  of  air. 

But  I  have  not  subjected  the  bubbles  of  glacier-ice  to 
the  same  searching  examination.  I  have  tried  whether 
the  insertion  of  a  pin  would  produce  the  collapse  of  the 
bubbles,  but  it  did  not  appear  to  do  so.  I  also  made  a  few 
experiments  at  Rosenlaui,  with  warm  water,  but  the  result 


"LIQUID   LIBERTY."  361 

was  not  satisfactory.  That  ice  melts  internally  at  the 
surfaces  of  the  bubbles  is,  I  think,  rendered  certain  by 
my  experiments,  but  whether  the  water-cells  of  glacier-ice 
are  entirely  due  to  such  melting,  subsequent  observers 
will  no  doubt  determine. 

I  have  found  these  composite  bubbles  at  all  parts  of 
glaciers  ;  in  the  ice  of  the  moraines,  over  which  a  protec- 
tive covering  had  been  thrown ;  in  the  ice  of  sand-cones, 
after  the  removal  of  the  superincumbent  debris  ;  also  in 
ice  taken  from  the  roofs  of  caverns  formed  in  the  glacier, 
and  which  the  direct  sun-light  could  hardly  by  any  possi- 
bility attain.  That  ice  should  liquefy  at  the  surface  of  a 
cavity  is,  I  think,  in  conformity  with  all  we  know  con- 
cerning the  physical  nature  of  heat.  Regarding  it  as  a 
motion  of  the  particles,  it  is  easy  to  see  that  this  motion 
is  less  restrained  at  the  surface  of  a  cavity  than  in  the 
solid  itself,  where  the  oscillation  of  each  atom  is  controlled 
by  the  particles  which  surround  it ;  hence  liquid  liberty, 
if  I  may  use  the  term,  is  first  attained  at  the  surface. 
Indeed,  I  have  proved  by  experiment  that  ice  may  be 
melted  internally  by  heat  which  has  been  conducted 
through  its  external  portions  without  melting  them.  These 
facts  are  the  exact  complements  of  those  of  "  regelation  ;" 
for  here,  two  moist  surfaces  of  ice  being  brought  into 
close  contact,  their  liquid  liberty  is  destroyed  and  the 
surfaces  freeze  together. 


362  MOULIN   ON   GRINDELWALD   GLACIER. 


THE    MOULINS. 
(25.) 

THE  first  time  I  had  an  opportunity  of  seeing  these  re- 
markable glacier-chimneys  was  in  the  summer  of  1856, 
upon  the  lower  glacier  of  Grindelwald.  Mr.  Huxley  was 
my  companion  at  the  time,  and  on  crossing  the  so-called 
Eismeer  we  heard  a  sound  resembling  the  rumble  of  dis- 
tant thunder,  which  proceeded  from  a  perpendicular  shaft 
formed  in  the  ice,  and  into  which  a  resounding  cataract 
discharged  itself.  The  tube  in  fact  resembled  a  vast 
organ-pipe,  whose  thunder-notes  were  awakened  by  the 
concussion  of  the  falling  water,  instead  of  by  the  gentle 
flow  of  a  current  of  air.  Beside  the  shaft  our  guide 
hewed  steps,  on  which  we  stood  in  succession,  and  looked 
into  the  tremendous  hole.  Near  the  first  shaft  was  a  sec- 
ond and  smaller  one,  the  significance  of  which  I  did  not 
then  understand  ;  it  was  not  more  than  20  feet  deep,  but 
seemed  filled  with  a  liquid  of  exquisite  blue,  the  colour 
being  really  due  to  the  magical  shimmer  from  the  walls 
of  the  rnoulin,  which  was  quite  empty.  As  far  as  we  could 
see,  the  large  shaft  was  vertical,  but  on  dropping  a  stone 
into  it  a  shock  was  soon  heard,  and  after  a  succession  of 
bumps,  which  occupied  in  all  seven  seconds,  we  heard  the 
stone  no  more.  The  depth  of  the  moulin  could  not  be 
thus  ascertained,  but  we  soon  found  a  second  and  still 
larger  one  which  gave  us  better  data.  A  stone  dropped 
into  this  descended  without  interruption  for  four  seconds, 
when  a  concussion  was  heard  ;  and  three  seconds  after- 
wards the  final  shock  was  audible  :  there  was  thus  but  a 
single  interruption  in  the  descent.  Supposing  all  the  ac- 
quired velocity  to  have  been  destroyed  by  the  shock,  by 


DEPTH  OF   SHAFT.  363 

adding  the  space  passed  over  by  the  stone  in  four  and  in 
three  seconds  respectively,  and  making  allowance  for  the 
time  required  by  the  sound  to  ascend  from  the  bottom,  we 
find  the  depth  of  the  shaft  to  be  about  345  feet.  There 
is,  however,  no  reason  to  suppose  that  this  measures  the 
depth  of  the  glacier  at  the  place  referred  to.  These  shafts 
are  to  be  found  in  almost  all  great  glaciers ;  they  are  very 
numerous  in  the  Unteraar  glacier,  numbers  of  them  how- 
ever being  empty.  On  the  Mer  de  Glace  they  are  always 
to  be  found  in  the  region  of  Trelaporte,  one  of  the  shafts 
there  being,  par  excellence,  called  the  Grand  Moulin. 
Many  of  them  also  occur  on  the  Glacier  de  Le*chaud. 

As  truly  observed  by  M.  Agassiz,  these  moulins  occur 
only  at  those  parts  of  the  glacier  which  are  not  much  rent 
by  fissures,  for  only  at  such  portions  can  the  little  rills 
produced  by  superficial  melting  collect  to  form  streams 
of  any  magnitude.  The  valley  of  unbroken  ice  formed  in 
the  Mer  de  Glace  near  Trelaporte  is  peculiarly  favourable 
for  the  collection  of  such  streams ;  we  see  the  little  rills 
commencing,  and  enlarging  by  the  contributions  of  others, 
the  trunk-rill  pouring  its  contents  into  a  little  stream 
which  stretches  out  a  hundred  similar  arms  over  the  sur- 
face of  the  glacier.  Several  such  streams  join,  and  finally 
a  considerable  brook,  which  receives  the  superficial  drain- 
age of  a  large  area,  cuts  its  way  through  the  ice. 

But  although  this  portion  of  the  glacier  is  free  from 
those  long-continued  and  permanent  strains  which,  having 
once  rent  the  ice,  tend  subsequently  to  widen  the  rent  and 
produce  yawning  crevasses,  it  is  not  free  from  local  strains 
sufficient  to  produce  cracks  which  penetrate  the  glacier  to 
a  great  depth.  Imagine  such  a  crack  intersecting  such 
a  glacier-rivulet  as  we  have  described.  The  water  rushes 
down  it,  and  soon  scoops  a  funnel  large  enough  to  engulf 
the  entire  stream.  The  moulin  is  thus  formed,  and,  as  the 
ice  moves  downward,  the  sides  of  the  crack  are  squeezed 


364  MOULINS  EXPLAINED. 

together  and  regelated,  the  seam  which  marks  the  line 
of  junction  being  in  most  cases  distinctly  visible.  But  as 
the  motion  continues,  other  portions  of  the  glacier  come 
into  the  same  state  of  strain  as  that  which  produced  the 
first  crack ;  a  second  one  is  formed  across  the  stream, 
the  old  shaft  is  forsaken,  and  a  new  one  is  hollowed  out, 
in  which  for  a  season  the  cataract  plays  the  thunderer.  I 
have  in  some  cases  counted  the  forsaken  shafts  of  six 
old  moulins  in  advance  of  an  active  one.  Not  far  from 
the  Grand  Moulin  of  the  Mer  de  Glace  in  1857  there  was 
a  second  empty  shaft,  which  evidently  communicated  by 
a  subglacial  duct  with  that  into  which  the  torrent  was 
precipitated.  Out  of  the  old  orifice  issued  a  strong  cold 
blast,  the  air  being  manifestly  impelled  through  the  duct 
by  the  falling  water  of  the  adjacent  moulin. 

These  shafts  are  always  found  in  the  same  locality  ;  the 
portion  of  the  Mer  de  Glace  to  which  I  have  referred  is 
never  without  them.  Some  of  the  guides  affirm  that  they 
are  motionless  ;  and  a  statement  of  Prof.  Forbes  has  led 
to  the  belief  that  this  was  also  his  opinion.*  M.  Agassiz, 
however,  observed  the  motion  of  some  of  these  shafts 
upon  the  glacier  of  the  Aar ;  and  when  on  the  spot  in 
1857,  I  was  anxious  to  decide  the  point  by  accurate 
measurements  with  the  theodolite. 

My  friend  Mr.  Hirst  took  charge  of  the^  instrument,  and 
on  the  28th  of  July,  I  fixed  a  single  stake  beside  the  Grand 
Moulin,  in  a  straight  line  between  a  station  at  Trelaporte 
and  a  well-defined  mark  on  the  rock  at  the  opposite  side 
of  the  valley.  On  the  31st,  the  displacement  of  the  stake 
amounted  to  50  inches,  and  on  the  1st  of  August  it  had 
moved  74|  inches, — the  moulin,  to  all  appearance,  occupy- 
ing throughout  the  same  position  with  regard  to  the  stake. 

*  "  Every  year,  and  year  after  year,  the  watercourses  follow  the  same 
lines  of  direction,  —  their  streams  are  precipitated  into  the  heart  of  the 
glacier  by  vertical  funnels,  called  'moulins,'  at  the  very  same  points."  — 
Forbes's  Fourth  Letter  upon  Glaciers  :  "  Occ.  Pap.,"  p.  29. 


MOTION  OF  THE  MOULINS.  365 

To  render  this  certain,  moreover,  we  subsequently  drove 
two  additional  stakes  into  the  ice,  thus  enclosing  the 
mouth  of  the  shaft  in  a  triangle.  On  the  8th  of  August 
the  displacements  were  measured  and  gave  the  following 
results :  — 

Total  Motion. 
First  (old)  stake          .         .        .        .         198  inches. 

Second  (new)  do 123      " 

Third 124      " 

The  old  stake  had  been  fixed  for  11  days,  and  its  daily 
motion  —  which  was  alse  that  of  the  moulin  —  averaged 
18  inches  a  day.  Hence  the  moulins  share  the  general 
motion  of  the  glacier,  and  their  apparent  permanence  is 
not,  as  has  been  alleged,  a  proof  of  the  semi-fluidity  of  the 
glacier,  but  is  due  to  the  breaking  of  the  ice  as  it  passes 
the  place  of  local  strain. 

Wishing  to  obtain  some  estimate  as  to  the  depth  of  the 
ice,  Mr.  Hirst  undertook  the  sounding  of  some  of  the 
moulins  upon  the  Glacier  de  Le'chaud,  making  use  of  a 
tin.  vessel  filled  with  lumps  of  lead  and  iron  as  a  weight. 
The  cord  gave  way  and  he  lost  his  plummet.  To  measure 
the  depth  of  the  Grand  Moulin,  we  obtained  fresh  cord 
from  Chamouni,  to  which  we  attached  a  four-pound  weight. 
Into  a  cavity  at  the  bottom  of  the  weight  we  stuffed  a  quan- 
tity of  butter,  to  indicate  the  nature  of  the  bottom  against 
which  the  weight  might  strike.  The  weight  was  dropped 
into  the  shaft,  and  the  cord  paid  out  until  its  slackening 
informed  us  that  the  weight  had  come  to  rest ;  by  shaking 
the  string,  however,  and  walking  round  the  edge  of  the 
shaft,  the  weight  was  liberated,  and  sank  some  distance  fur- 
ther. The  cord  partially  slackened  a  second  time,  but  the 
strain  still  remaining  was  sufficient  to  render  it  doubtful 
whether  it  was  the  weight  or  the  action  of  the  falling  water 
which  produced  it.  We  accordingly  paid  out  the  cord  to 
the  end,  but,  on  withdrawing  it,  found  that  the  greater  part 
of  it  had  been  coiled  and  knotted  up  by  the  falling  water. 


366     DEPTH  OF  "GRAND  MOULIN"  SOUGHT. 

We  uncoiled,  and  sounded  again.  At  a  depth  of  132 
feet  the  weight  reached  a  ledge  or  protuberance  of  ice, 
and  by  shaking  and  lifting  it,  it  was  caused  to  descend  31 
feet  more.  A  depth  of  163  feet  was  the  utmost  we  could 
attain.  We  sounded  the  old  moulin  to  a  depth  of  90  feet ; 
while  a  third  little  shaft,  beside  the  large  one,  measured 
only  18  feet  in  depth.  We  could  see  the  water  escape 
from  it  through  a  lateral  canal  at  its  bottom,  and  doubt- 
less the  water  of  the  Grand  Moulin  found  a  similar  exit. 
There  was  no  trace  of  dirt  upon,  the  butter,  which  might 
have  indicated  that  we  had  reached  the  bed  of  the  glacier. 


DIRT-BANDS   OF  THE  MER  DE   GLACE,   AS   SEEN  FROM  A  POINT 
NEAR   THE   FLEGERE. 


Fig.  35. 


DIRT-BANDS  FROM  THE  FLEGERE.  367 

DIRT-BANDS  OF  THE  MER  DE  GLACE. 

(26.) 


368  DIRT-BANDS  FROM  LES  CHARMOZ. 

is  derived  from  the  Col  du  Ge*ant.  They  do  not  quite 
extend  to  the  end  of  the  glacier,  being  obliterated  by  the 
dislocation  of  the  ice  upon  the  frozen  cascade  of  Des  Bois. 

Let  us  now  proceed  across  the  valley  of  Chamouni  to 
the  Montanvert ;  where,  climbing  the  adjacent  heights  to 
an  elevation  of  six  or  eight  hundred  feet  above  the  hotel, 
we  command  a  view  of  the  Mer  de  Glace,  from  Tre*laporte 
almost  to  the  commencement  of  the  Glacier  des  Bois.  It 
was  from  this  position  Professor  Forbes  first  observed  the 
bands.  Fifteen,  sixteen,  and  seventeen  years  later  I  ob- 
served them  from  the  same  position.  The  number  of 
bands  which  Professor  Forbes  counted  from  this  position 
was  eighteen,  with  which  my  observations  agree.  The 
entire  series  of  bands  which  I  observed,  with  the  excep- 
tion of  one  or  two,  must  have  been  the  successors  of 
those  observed  by  Professor  Forbes  ;  and  my  finding  the 
same  number  after  an  interval  of  so  many  years  proves 
that  the  bands  must  be  due  to  some  regularly  recurrent 
cause.  Fig.  36  represents  the  bands  as  seen  from  the 
heights  adjacent  to  the  Montanvert. 

I  would  here  direct  attention  to  an  analogy  between  a 
glacier  and  a  river,  which  may  be  observed  from  the 
heights  above  the  Montanvert,  but  to  which  no  reference, 
as  far  as  I  know,  has  hitherto  been  made.  When  a  river 
meets  the  buttress  of  a  bridge,  the  water  rises  against  it, 
and,  on  sweeping  round  it,  forms  an  elevated  ridge,  be- 
tween which  and  the  pier  a  depression  occurs  which  varies 
in  depth  with  the  force  of  the  current.  This  effect  is 
shown  by  the  Mer  de  Glace  on  an  exaggerated  scale. 
Sweeping  round  Trelaporte,  the  ice  pushes  itself  beyond 
the  promontory  in  an  elevated  ridge,  from  which  it  drops 
by  a  gradual  slope  to  the  adjacent  wall  of  the  valley,  thus 
forming  a  depression  typified  by  that  already  alluded  to. 
A  similar  effect  is  observed  at  the  opposite  side  of  thej 
glacier  on  turning  round  the  Echelets  ;  and  both  combine  j 


DIRT-BANDS   OF   THE  MEU   DE   GLACE,   AS   SEEN    PROM 
LES    CHAKMOZ. 

Fig.  36. 


UIRT-BANDS  OB"  THE   MEU   DE   GLACE,    AS  SEEN   FROM   THK 
CLEFT    STATION,   TRELAPOKTE. 

Fig.  37. 


FROM  THE  CLEFT  STATION.  369 

;o  form  a  kind  of  skew  surface.  A  careful  inspection  of 
;he  frontispiece  will  detect  this  peculiarity  in  the  shape 
of  the  glacier. 

From  neither  of  the  stations  referred  to  do  we  obtain 
any  clue  to  the  origin  of  the  dirt-bands.  A  stiff  but 
Peasant  climb  will  place  us  in  that  singular  cleft  in  the 
cliffy  mountain-ridge  which  is  seen  to  the  right  of  the 
frontispiece  ;  and  from  it  we  easily  attain  the  high  plat- 
form of  rock  immediately  to  the  left  of  it.  We  stand 
here  high  above  the  promontory  of  Trelaporte,  and  oc- 
cupy the  finest  station  from  which  the  Mer  de  Glace  and 
ts  tributaries  can  be  viewed.  From  this  station  we  trace 
he  dirt-bands  over  most  of  the  ice  that  we  have  already 
canned,  and  have  the  further  advantage  of  being  able  to 
bllow  them  to  their  very  source. 

This  source  is  the  grand  ice-cascade  which  descends  in 

succession  of  precipices  from  the  plateau  of  the  Col  du 
Gre*ant  into  the  valley  which  the  Glacier  du  Geant  fills. 
We  see  from  our  present  point  of  view  that  the  bands  are 
confined  to  the  portion  of  the  glacier  which  has  descended 
he  cascade.  Fig.  37  represents  the  bands  as  seen  from 
he  Cleft  station  above  Trdlaporte. 

We  are  now  however  at  such  a  height  above  the  glacier, 
ind  at  such  a  distance  from  the  base  of  the  cascade,  that 

e  can  form  but  an  imperfect  notion  of  the  true  contour 
>f  the  surface.  Let  us  therefore  descend,  and  walk  up 
he  Glacier  du  Ge*ant  towards  the  cascade.  At  first  our 
•oad  is  level,  but  we  gradually  find  that  at  certain  inter- 
rals  we  have  to  ascend  slopes  which  follow  each  other  in 
uccession,  each  being  separated  from  its  neighbour  by  a 
•pace  of  comparatively  level  ice.  The  slopes  increase  in 
.teepness  as  we  ascend ;  they  are  steepest,  moreover,  on 
he  right-hand  side  of  the  glacier,  where  it  is  bounded  by 
hat  from  the  Pe*riades,  and  at  length  we  are  unable  to 
•limb  them  without  the  aid  of  an  axe.  Soon  afterwards 


370       SNOW-BANDS  ON  THE  GLACIER  DU  GEANT. 

the  dislocation  of  the  glacier  becomes  considerable ;  we 
are  lost  in  the  clefts  and  depressions  of  the  ice,  and  are 
unable  to  obtain  a  view  sufficiently  commanding  to  sub- 
due these  local  appearances  and  convey  to  us  the  general 
aspect.  We  have  at  all  events  satisfied  ourselves  that  on 
the  upper  portion  of  the  glacier  a  succession  of  undula- 
tions exist,  which  sweep  transversely  across  it.  The  term 
"  wrinkles,"  applied  to  them  by  Prof.  Forbes,  is  highly 
suggestive  of  the  appearance  which  they  present. 

From  the  Cleft  station  bands  of  snow  may  also  be  seen 
partially  crossing  the  glacier  in  correspondence  with  the 
undulations  upon  its  surface.  If  the  quantity  deposited 
the  winter  previous  be  large,  and  the  heat  of  summer  not 
too  great,  these  bands  extend  quite  across  the  glacier. 
They  were  first  observed  by  Professor  Forbes  in  1843. 
In  his  Fifth  Letter  is  given  an  illustrative  diagram,  which, 
though  erroneous  as  regards  the  position  of  the  veined 
structure,  is  quite  correct  in  limiting  the  snow-bands  to 
the  Glacier  du  Geant  proper. 

At  the  place  where  the  three-  welded  tributaries  of  the 
Mer  de  Glace  squeeze  themselves  through  the  strait  of 
Trelaporte,  the  bands  undergo  a  considerable  modification 
in  shape.  Near  their  origin  they  sweep  across  the  Glacier 
du  Ge*ant  in  gentle  curves,  with  their  convexities  directed 
downwards ;  but  at  Trelaporte  these  curves,  the  chords 
of  which  a  short  time  previous  measured  a  thousand  yards 
in  length,  have  to  squeeze  themselves  through  a  space  of 
four  hundred  and  ninety-five  yards  wide  ;  and  as  might 
be  expected,  they  are  here  suddenly  sharpened.  The 
apex  of  each  being  thrust  forward,  they  take  the  form  of 
sharp  hyperbolas,  and  preserve  this  character  throughout 
the  entire  length  of  the  Mer  de  Glace. 

I  would  now  conduct  the  reader  to  a  point  from  which 
a  good  general  view  of  the  ice  cascade  of  the  Ge*ant  is 
attainable.  From  the  old  moraine  near  the  lake  of  the 


FORBES'S  EXPLANATION.  371 

Tacul  we  observe  the  ice,  as  it  descends  the  fall,  to  be 
broken  into  a  succession  of  precipices.  It  would  appear  as 
if  the  glacier  had  its  back  periodically  broken  at  the  sum- 
mit of  the  fall,  and  formed  a  series  of  vast  chasms  sepa- 
rated from  each  other  by  cliffy  ridges  of  corresponding 
size.  These,  as  they  approach  the  bottom  of  the  fall,  be- 
come more  and  more  toned  down  by  the  action  of  sun 
and  air,  and  at  some  distance  below  the  base  of  the  cas- 
cade they  are  subdued  so  as  to  form  the  transverse  undula- 
tions already  described.  These  undulations  are  more  and 
more  reduced  as  the  glacier  descends ;  and  long  before 
the  Tacul  is  attained,  every  sensible  trace  of  them  has 
disappeared.  The  terraces  of  the  ice-fall  are  referred  to  by 
Professor  Forbes  in  his  Thirteenth  Letter,  where  he  thus 
describes  them: — "The  ice-falls  succeed  one  another  at 
regulated  intervals,  which  appear  to  correspond  to  the  re- 
newal of  each  summer's  activity  in  those  realms  of  almost 
perpetual  frost,  when  a  swifter  motion  occasions  a  more 
rapid  and  wholesale  projection  of  the  mass  over  the  steep, 
thus  forming  curvilinear  terraces  like  vast  stairs,  which 
appear  afterwards  by  consolidation  to  form  the  remark- 
able protuberant  wrinkles  on  the  surface  of  the  Glacier 
du  G£ant." 

With  regard  to  the  cause  of  the  distribution  of  the  dirt 
in  bands,  Professor  Forbes  writes  thus  in  his  Third  Lefc- 
ter : — "I  at  length  assured  myself  that  it  was  entirely 
owing  to  the  structure  of  the  ice,  which  retains  the  dirt 
diffused  by  avalanches  and  the  weather  on  those  parts 
which  are  most  porous,  whilst  the  compacter  portion  is 
washed  clean  by  the  rain,  so  that  those  bands  are  nothing 
more  than  visible  traces  of  the  direction  of  the  internal 
icy  structure."  Professor  Forbes's  theory,  at  that  time, 
was  that  the  glacier  is  composed  throughout  of  a  series  of 
alternate  segments  of  hard  and  porous  ice,  in  the  latter 
of  which  the  dirt  found  a  lodgment.  I  do  not  know 


37-  TRANSVERSE   UNDULATIONS. 

whether  he  now  retains  his  first  opinion  ;  but  in  his  Fif- 
teenth Letter  he  speaks  of  accounting  for  "  the  less  com- 
pact structure  of  the  ice  beneath  the  dirt-band." 

It  appears  to  me  that  in  the  above  explanation  cause 
has  been  mistaken  for  effect.  The  ice  on  which  the  dirt- 
bands  rest  certainly  appears  to  be  of  a  spongier  character 
than  the  cleaner  intermediate  ice  :  but  instead  of  this 
being  the  cause  of  the  dirt-bands,  the  latter,  I  imagine, 
by  their  more  copious  absorption  of  the  sun's  rays  and 
the  consequent  greater  disintegration  of  the  ice,  are  the 
cause  of  the  apparent  porosity.  I  have  not  been  able  to 
detect  any  relative  porosity  in  the  "  internal  icy  struc- 
ture/' nor  am  I  able  to  find  in  the  writings  of  Professor 
Forbes  a  description  of  the  experiments  whereby  he  satis- 
fied himself  that  this  assumed  difference  exists. 

Several  days  of  the  summer  of  1857  were  devoted  by 
me  to  the  examination  of  these  bands.  I  then  found  the 
bases  and  the  frontal  slopes  of  the  undulations  to  which  I 
have  referred  covered  with  a  fine  brown  mud.  These  slopes 
were  also,  in  some  cases,  covered  with  snow,  which  the 
great  heat  of  the  weather  had  not  been  able  entirely  to  re- 
move. At  places  where  the  residue  of  snow  was  small,  its 
surface  was  exceedingly  dirty, — so  dirty,  indeed,  that  it  ap- 
peared as  if  peat-mould  had  been  strewn  over  it ;  its  edges 
particularly  were  of  a  black  brown.  It  was  perfectly  man- 
ifest that  this  snow  formed  a  receptacle  for  the  fine  dirt 
transported  by  the  innumerable  little  rills  which  trickled 
over  the  glacier.  The  snow  gradually  wasted,  but  it  left 
its  sediment  behind,  and  thus  each  of  the  snowy  bands  ob- 
served by  Professor  Forbes  in  1843  contributed  to  produce 
an  appearance  perfectly  antithetical  to  its  own.  I  have 
said  that  the  frontal  slopes  of  the  undulations  were  thus 
covered ;  and  it  was  on  these,  and  not  in  the  depressions, 
that  the  snow  principally  rested.  The  reason  of  this  is  to 
be  found  in  the  bearing-  of  the  Glacier  du  Geant,  which, 


INFLUENCE  OF  DIRECTION  OF   GLACIER.          373 

looking  downwards,  is  about  fourteen  degrees  east  of  the 
meridian.*  Hence  the  frontal  slopes  of  the  undulations 
have  a  northern  aspect,  and  it  is  this  circumstance  which, 
in  my  opinion,  causes  the  retention  of  the  snow  upon  them. 
Irrespective  of  the  snow,  the  mere  tendency  of  the  dirt  to 
accumulate  at  the  bases  of  the  undulations  would  also 
produce  bands,  and  indeed  does  so  on  many  glaciers ;  but 
the  precision  and  beauty  of  the  dirt-bands  of  the  Mer  de 
Glace  are,  I  think,  to  be  mainly  referred  to  the  intercep- 
tion by  the  snow  of  the  fine  dark  mud  before  referred  to 
on  the  northern  slopes  of  its  undulations. 

Were  the  statements  of  some  writers  upon  this  subject 
well  founded,  or  were  the  dirt-band,  as  drawn  upon  the 
map  of  Professor  Forbes,  correctly  shown,  this  explanation 
could  not  stand  a  moment.  It  has  been  urged  that  the  dirt- 
bands  cannot  thus  belong  to  a  single  tributary  of  the  Mer 
de  Glace  ;  for  if  they  did,  they  would  be  confined  to  that 
tributary  upon  the  trunk-glacier  ;  whereas  the  fact  is  that 
they  extend  quite  across  the  trunk,  and  intersect  the 
moraines  which  divide  the  Glacier  du  Ge*ant  from  its  fel- 
low-tributaries. From  my  first  acquaintance  with  the 
Mer  de  Glace  I  had  reason  to  believe  that  this  statement 
was  incorrect ;  but  last  year  I  climbed  a  third  time  to  the 
Cleft  station  for  the  purpose  of  once  more  inspecting  the 
bands  from  this  fine  position.  I  was  accompanied  by 
Dr.  Frankland  and  Auguste  Balmat,  and  I  drew  the  at- 
tention of  both  particularly  to  this  point.  Neither  of  them 
could  discern,  nor  could  I,  the  slightest  trace  of  a  dirt- 
band  crossing  any  one  of  the  moraines.  Upon  the  trunk- 
stream  they  were  just  as  much  confined  to  the  Glacier  du 
Ge*ant  as  ever.  If  the  bands  even  existed  east  of  the  mo- 

#  In  the  large  map  of  Professor  Forbes  the  bearing  of  the  valley  is  nearly 
sixty  degrees  west  of  the  meridian ;  but  this  is  caused  by  the  true  north  being 
drawn  on  the  wrong  side  of  the  magnetic  north  ;  thus  making  the  declination 
easterly,  instead  of  westerly.  In  the  map  in  Johnson's  "  Physical  Atlas  "  this 
mistake  is  corrected. 


3T4 


BANDS  DO  NOT  CROSS  MORAINES. 


raines,  they  could  not  be  seen,  the  dirt  on  this  part  of  the 
glacier  being  sufficient  to  mask  them. 

The  following  interesting  fact  may  perhaps  have  contri- 
buted to  the  production  of  the  error  referred  to.  Opposite 
to  Trelaporte  the  eastern  arms  of  the  dirt-bands  run  so 
obliquely  into  the  moraine  of  La  Noire  that  the  latter 
appears  to  be  a  tangent  to  them.  But  this  moraine  runs 
along  the  Mer  de  Glace,  not  far  from  its  centre,  and  con- 
sequently the  point  of  contact  of  each  dirt-band  with  the 
moraine  moves  more  quickly  than  the  point  of  contact  of 
the  western  arm  of  the  same  band  with  the  side  of  the 
valley.  Hence  there  is  a  tendency  to  straighten  the  bands ; 
and  at  some  distance  down  the  glacier  the  effect  of  this  is 
seen  in  the  bands  abutting  against  the  moraine  of  La  Noire 
at  a  larger  angle  than  before.  The  branches  thus  abutting 
have,  I  believe,  been  ideally  prolonged  across  the  moraines. 
On  the  map  published  by  Prof.  Forbes  in  1843  the 
bands  are  shown  crossing  the  medial  moraines  of  the  Mer  de 
Glace ;  and  they  are  also  thus  drawn  on 
the  map  in  Johnson's  "  Physical  Atlas," 
published  in  1849.  The  text  is  also  in 
accordance  with  the  map  :  —  "  Opposite  to 
the  Montanvert,  and  beyond  les  Echelets, 
the  curved  loops  (dirt-bands)  extend  across 
the  entire  glacier.  They  are  single,  and 
therefore  cut  the  medial  moraine,  though 
at  a  very  slight  angle."  ("  Travels,"  p. 
166.)  The  italics  here  belong  to  Prof. 
Forbes.  In  order  to  help  future  observers 
to  place  this  point  beyond  doubt,  I  annex, 
in  Fig.  38,  a  portion  of  the  map  of  the 
Mer  de  Glace  taken  from  the  Atlas  re- 
ferred to.  If  it  be  compared  with  Fig.  35,  the  difference 
between  Prof.  Forbes  and  myself  will  be  clearly  seen.  The 
portion  of  the  glacier  represented  in  both  diagrams  may 


Fig.  38. 


ANNUAL  "KINGS."  375 

be  viewed  from  the  point  near  the  Flegere  already  re- 
ferred to. 

The  explanation  which  I  have  given  involves  three  con- 
siderations : — the  transverse  breaking  of  the  glacier  on  the 
cascade,  and  the  gradual  accumulation  of  the  dirt  in  the 
hollows  between  the  ridges  ;  the  subsequent  toning  down 
of  the  ridges  to  gentle  protuberances  which  sweep  across 
the  glacier ;  and  the  collection  of  the  dirt  upon  the  slopes 
and  at  the  bases  of  these  protuberances.  Whether  the 
periods  of  transverse  fracture  are  annual  or  not,  whether 
the  "wrinkles"  correspond  to  a  yearly  gush,  and  whether, 
consequently,  the  dirt-bands  mark  the  growth  of  a  glacier 
as  the  "  annual  rings  "  mark  the  growth  of  a  tree,  I  do  not 
know.  It  is  a  conjecture  well  worthy  of  consideration ;  but 
it  is  only  a  conjecture,  which  future  observation  may  either 
ratify  or  refute. 


376  GENERAL  APPEARANCE. 

THE   VEINED   STRUCTURE   OF   GLACIERS. 
(2T.) 

THE  general  appearance  of  the  veined  structure  may  be 
thus  briefly  described.  The  ice  of  glaciers,  especially  mid- 
way between  their  mountain-sources  and  their  inferior  ex- 
tremities, is  of  a  whitish  hue,  caused  by  the  number  of 
small  air-bubbles  which  it  contains,  and  which,  no  doubt, 
constitute  the  residue  of  the  air  originally  entrapped  in  the 
interstices  of  the  snow  from  which  it  has  been  derived. 
Through  the  general  whitish  mass,  at  some  places,  innume- 
rable parallel  veins  of  clearer  ice  are  drawn,  which  usually 
present  a  beautiful  blue  colour,  and  give  the  ice  a  laminated 
appearance.  The  cause  of  the  blueness  is,  that  the  air- 
bubbles,  distributed  so  plentifully  through  the  general 
mass,  do  not  exist  in  the  veins,  or  only  in  comparatively 
small  numbers. 

In  different  glaciers,  and  in  different  parts  of  the  same 
glacier,  these  veins  display  various  degrees  of  perfection. 
On  the  clean  unweathered  walls  of  some  crevasses,  and  in 
the  channels  worn  in  the  ice  by  glacier-streams,  they  are 
most  distinctly  seen,  and  are  often  exquisitely  beautiful. 
They  are  not  to  be  regarded  as  a  partial  phenomenon,  or 
as  affecting  the  constitution  of  glaciers  to  a  small  extent 
merely.  A  large  portion  of  the  ice  of  some  glaciers  is  thus 
affected.  The  greater  part,  for  example,  of  the  Mer  de 
Glace  consists  of  this  laminated  ice ;  and  the  whole  of 
the  Glacier  of  the  Rhone,  from  the  base  of  the  ice-cascade 
downwards,  is  composed  of  ice  of  the  same  description. 

Those  who  have  ascended  Snowdon,  or  wandered  among 
the  hills  of  Cumberland,  or  even  walked  in  the  environs  of 
Leeds,  Blackburn,  and  other  towns  in  Yorkshire  and  Lan- 
cashire, where  the  stratified  sandstone  of  the  district  is 


GKOOVES   ON  THE    SURFACE    OF    GLACIERS.       377 

used  for  building  purposes,  may  have  observed  the 
weathered  edges  of  the  slate  rocks  or  of  the  building- 
stone  to  be  grooved  and  furrowed.  Some  laminae  of  such 
rocks  withstand  the  action  of  the  atmosphere  better  than 
others,  and  the  more  resistent  ones  stand  out  in  ridges 
after  the  softer  parts  between  them  have  been  eaten  away. 
An  effect  exactly  similar  is  observed  where  the  laminated 
ice  of  glaciers  is  exposed  to  the  action  of  the  sun  and  air. 
Little  grooves  and  ridges  are  formed  upon  its  surface,  the 
more  resistent  plates  protruding  after  the  softer  material 
between  them  has  been  melted  away. 

One  consequence  of  this  furrowing  is,  that  the  light  dirt 
scattered  by  the  winds  over  the  surface  of  the  glacier  is 
gradually  washed  into  the  little  grooves,  thus  forming  fine 
lines  resembling  those  produced  by  the  passage  of  a  rake 
over  a  sanded  walk.  These  lines  are  a  valuable  index  to 
some  of  the  phenomena  of  motion.  From  a  position  on 
the  ice  of  the  Glacier  du  Ge*ant  a  little  higher  up  than  Tre*- 
laporte  a  fine  view  of  these  superficial  groovings  is  obtained ; 
but  the  dirt-lines  are  not  always  straight.  A  slight  power 
of  independent  motion  is  enjoyed  by  the  separate  parts  into 
which  a  glacier  is  divided  by  its  crevasses  and  dislocations, 
and  hence  it  is,  that,  at  the  place  alluded  to,  the  dirt-lines 
are  bent  hither  and  thither,  though  the  ruptures  of  conti- 
nuity are  too  small  to  affect  materially  the  general  direction 
of  the  structure.  On  the  glacier  of  the  Talefre  I  found 
these  groovings  useful  as  indicating  the  character  of  the 
forces  to  which  the  ice  near  the  summit  of  the  fall  is  sub- 
jected. The  ridges  between  the  chasms  are  in  many  cases 
violently  bent  and  twisted,  while  the  adjacent  groovings 
enable  us  to  see  the  normal  position  of  the  mass. 

The  veined  structure  has  been  observed  by  different 

travellers ;   but  it  was  probably  first  referred  to  by  Sir 

David   Brewster,   who   noticed   the   veins    of   the    Mer 

de  Glace  on  the  10th  of  September,  1814.     It  was  also 

25 


878  GUYOT'S  OBSERVATIONS. 

observed  by  General  Sabine,*  by  Rendu,  by  Agassiz,  and 
no  doubt  by  many  others ;  but  the  first  clear  description 
of  it  was  given  by  M.  Guyot,  in  a  communication  present- 
ed to  the  Geological  Society  of  France  in  1838.  I  quote 
the  following  passage  from  this  paper :  —  "I  saw  under  my 
feet  the  surface  of  the  entire  glacier  covered  with  regular 
furrows  from  one  to  two  inches  wide,  hollowed  out  in  a  half 
snowy  mass,  and  separated  by  protruding  plates  of  harder 
and  more  transparent  ice.  It  was  evident  that  the  mass 
of  the  glacier  here  was  composed  of  two  sorts  of  ice,  one 
that  of  the  furrows,  snowy  and  more  easily  melted ;  the 
other  that  of  the  plates,  more  perfect,  crystalline,  glassy, 
and  resistent ;  and  that  the  unequal  resistance  which  the 
two  kinds  of  ice  presented  to  the  atmosphere  was  the  cause 
of  the  furrows  and  ridges.  After  having  followed  them  for 
several  hundreds  of  yards,  I  reached  a  fissure  twenty  or 
thirty  feet  wide,  which,  as  it  cut  the  plates  and  furrows  at 
right  angles,  exposed  the  interior  of  the  glacier  to  a  depth  of 

*  In  reply  to  a  question  in  connexion  with  this  subject,  General  Sabine 
has  favoured  me  with  the  following  note :  — 

"  MY  DEAR  TYNDALL, 

"It  was  in  the  summer  of  1841,  at  the  Lower  Grindelwald  Glacier, 
that  I  first  saw,  and  was  greatly  impressed  and  interested  by  examining  and 
endeavouring  to  understand  (in  which  I  did  not  succeed),  the  veined  structure 
of  the  ice.  I  do  not  remember  when  I  mentioned  it  to  Forbes,  but  it  must  be 
before  1843,  because  it  is  noticed  in  his  book,  p.  29.  I  had  never  observed  it 
in  the  glaciers  of  Spitzbergen  or  Baffin's  Bay,  or  in  the  icebergs  of  the  shores 
and  straits  of  Davis  or  Barrow.  I  feel  the  more  confident  of  this,  because, 
when  I  first  saw  the  veined  structure  in  Switzerland,  my  Arctic  experience  was 
more  fresh  in  my  recollection,  and  I  recollected  nothing  like  it. 

"  Veins  are  indeed  not  uncommon  in  icebergs,  but  they  quite  resemble  veins 
in  rocks,  and  are  formed  by  water  filling  fissures  and  freezing  into  blue  ice, 
finely  contrasted  with  the  white  granular  substance  of  the  berg. 

"  The  ice  of  the  Grindelwald  Glacier  (where  I  examined  the  veined  struc- 
ture) was  broken  up  into  very  large  masses,  which  by  pressure  had  been  up- 
turned, so  that  a  very  poor  judgment  would  be  formed  of  the  direction  of  the 
veins  as  they  existed  in  the  glacier  before  it  had  broken  up. 

"  Sincerely  yours, 

"  Feb.  20, 1860."  "  EDWARD  SABINE. 


FORBES'S  RESEARCHES.  379 

thirty  or  forty  feet,  and  gave  a  beautiful  transverse  section 
of  the  structure.  As  far  as  my  vision  could  reach,  I  saw 
the  mass  of  the  glacier  composed  of  layers  of  snowy  ice, 
each  two  of  which  were  separated  by  one  of  the  plates  of 
which  I  have  spoken,  the  whole  forming  a  regularly  lami- 
nated mass,  which  resembled  certain  calcareous  slates." 

Previous  observers  had  mistaken  the  lamination  for 
stratification  ;  but  M.  Guyot  not  only  clearly  saw  that 
they  were  different,  but  in  the  comparison  which  he 
makes  he  touches,  I  believe,  on  the  true  cause  of  the  gla- 
cier-structure. He  did  not  hazard  an  explanation  of  the 
phenomenon,  and  I  believe  his  memoir  remained  un- 
printed.  In  1841  the  structure  was  noticed  by  Professor 
Forbes  during  his  visit  to  M.  Agassiz  on  the  Lower  Aar 
Glacier,  and  described  in  a  communication  presented  by 
him  to  the  Royal  Society  of  Edinburgh.  He  subsequently 
devoted  much  time  to  the  subject,  and  his  great  merit  in 
connexion  with  it  consists  in  the  significance  which  he 
ascribed  to  the  phenomenon  when  he  first  observed  it, 
and  in  the  fact  of  his  having  proved  it  to  be  a  constitu- 
tional feature  of  glaciers  in  general. 

The  first  explanation  given  of  those  veins  by  Professor 
Forbes  was,  that  they  were  small  fissures  formed  in  the 
ice  by  its  motion ;  that  these  were  filled  with  the  water 
of  the  melted  ice  in  summer,  which  froze  in  winter  so  as  to 
form  the  blue  veins.  This  is  the  explanation  given  in  his 
"  Travels,"  page  377  ;  and  in  a  letter  published  in  the 
"  Edinburgh  New  Philosophical  Journal,"  October,  1844, 
it  is  re-affirmed  in  these  words :  — "  With  the  abundance 
of  blue  bands  before  us  in  the  direction  in  which  the  dif- 
ferential motion  must  take  place,  (in  this  case  sensibly 
parallel  to  the  sides  of  the  glacier,)  it  is  impossible  to 
doubt  that  these  infiltrated  crevices  (for  such  they  un- 
doubtedly are)  have  this  origin."  This  theory  was  exam- 
ined by  Mr.  Huxley  and  myself  in  our  joint  paper  ;  but  it 


380  FORBES'S   THEORY. 

has  been  since  alleged  that  ours  was  unnecessary  labour, 
Prof.  Forbes  himself  having  in  his  Thirteenth  Letter  re- 
nounced the  theory,  and  substituted  another  in  its  place. 
The  latter  theory  differs,  so  far  as  I  can  understand  it, 
from  the  former  in  this  particular,  that  the  freezing'  of 
the  water  in  the  fissures  is  discarded,  their  sides  being 
now  supposed  to  be  united  "  by  the  simple  effects  of  time 
and  cohesion."  *  For  a  statement  of  the  change  which  his 
opinions  have  undergone,  I  would  refer  to  the  Prefatory 
Note  which  precedes  the  volume  of  "  Occasional  Papers  " 
recently  published  by  Prof.  Forbes  ;  but  it  would  have 
diminished  my  difficulty  had  the  author  given,  in  con- 
nexion with  his  new  volume,  a  more  distinct  statement  of 
his  present  views  regarding  the  veined  structure.  With 
many  of  his  observations  and  remarks  I  should  agree  ; 
with  many  others  I  cannot  say  whether  I  agree  or  not ; 
and  there  are  others  still  with  which  I  do  not  think  I 
should  agree  :  but  in  hardly  any  case  am  I  certain  of  his 
precise  views,  excepting,  indeed,  the  cardinal  one,  wherein 
he  and  others  agree  in  ascribing  to  the  structure  a  differ- 
ent origin  from  stratification.  Thus  circumstanced,  my 
proper  course,  I  think,  will  be  to  state  what  I  believe  to  be 
the  cause  of  the  structure,  and  leave  it  to  the  reader  to 
decide  how  far  our  views  harmonize ;  or  to  what  extent 
either  of  them  is  a  true  interpretation  of  nature. 

Most  of  the  earlier  observers  considered  the  structure  to 
be  due  to  the  stratification  of  the  mountain  snows, — a  view 
which  has  received  later  development  at  the  hands  of  Mr. 
John  Ball  ;  and  the  practical  difficulty  of  distinguishing 
the  undoubted  effects  of  stratification  from  the  phenomena 

*  In  a  letter  to  myself,  published  in  the  17th  volume  of  the  ".Philosophi- 
cal Magazine,"  Professor  Forbes  writes  as  follows: — "In  1846,  then,  I 
abandoned  no  part  of  the  theory  of  the  veined  structure,  on  which,  as  you 
say,  so  much  labour  has  been  expended,  except  the  admission,  always 
yielded  with  reluctance,  and  got  rid  of  with  satisfaction,  that  the  congelation 
of  water  in  the  crevices  of  the  glacier  may  extend  in  winter  to  a  great  depth.' 


USUAL  ASPECT  OF  BLUE  VEINS. 


381 


presented  by  structure,  entitles  this  view  to  the  fullest 
consideration.  The  blue  veins  of  glaciers  are,  however, 
not  always,  nor  even  generally,  such  as  we  should  expect 
to  result  from  stratification.  The  latter  would  furnish  us 
with  distinct  planes  extending  parallel  to  each  other  for 
considerable  distances  through  the  glacier ;  but  this, 
though  sometimes  the  case,  is  by  no  means  the  general 
character  of  the  structure.  We  observe  blue  streaks,  from 
a  few  inches  to  several  feet  in  length,  upon  the  walls  of 
the  same  crevasse,  and  varying  from  the  fraction  of  an 
inch  to  several  inches  in  thickness.  In  some  cases  the 
streaks  are  definitely  bounded,  giving  rise  to  an  appear- 
ance resembling  the  section  of  a  lens,  and  hence  called 
the  "lenticular  structure"  by  Mr.  Huxley  and  myself;  but 
more  usually  they  fade  away  in  pale  washy  streaks  through 


the  general  mass  of  the  whitish  ice. 
given  a  representation  of  the 
structure   as  it  is  very  com- 
monly exhibited  on  the  walls 
of  crevasses.    Its  aspect  is  not 
that  which  we  should  expect 
from  the  consolidation  of  sue-  (J 
cessive  beds  of  mountain  snow,  j 


In  Fig.  39  I  have 


Further,  at  the  bases  of  ice- 
cascades  the  structural  lami- 
nae are  usually  vertical :  below 
the  cascade  of  the  Talefre,  of 
the  Noire,  of  the  Strahleck 
branch  of  the  Lower  Grindel- 
wald  Glacier,  of  the  Ehone, 
and  other  ice-falls,  this  is  the 
case  ;  and  it  seems  extremely  difficult  to  conceive  that 
a  mass  horizontally  stratified  at  the  summit  of  the  fall, 
should,  in  its  descent,  contrive  to  turn  its  strata  perfectly 
on  end. 


Fig.  39. 


382  ILLUSTRATIVE  EXPERIMENTS. 

Again,  we  often  find  a  very  feebly  developed  structure 
at  the  central  portions  of  a  glacier,  while  the  lateral  por- 
tions are  very  decidedly  laminated.  This  is  the  case 
where  the  inclination  of  the  glacier  is  nearly  uniform 
throughout ;  and  where  no  medial  moraines  occur  to 
complicate  the  phenomenon.  But  if  the  veins  mark  the 
bedding,  there  seems  to  be  no  sufficient  reason  for  their 
appearance  at  the  lateral  portions  of  the  glacier,  and  their 
absence  from  the  centre. 

This  leads  me  to  the  point  at  which  what  I  consider  to 
be  the  true  cause  of  the  structure  may  be  referred  to. 
The  theoretic  researches  of  Mr.  Hopkins  have  taught  us 
a  good  deal  regarding  the  pressures  and  tensions  conse- 
quent upon  glacier-motion.  Aided  by  this  knowledge, 
and  also  by  a  mode  of  experiment  first  introduced  by 
Professor  Forbes,  I  will  now  endeavour  to  explain  the 
significance  of  the  fact  referred  to  in  the  last  paragraph. 
If  a  plastic  substance,  such  as  mud,  flow  down  a  sloping 
canal,  the  lateral  portions,  being  held  back  by  friction, 
will  be  outstripped  by  the  central  ones.  When  the  flow 
is  so  regulated  that  the  velocity  of  a  point  of  the  centre 
shall  not  vary  throughout  the  entire  length  of  the  canal, 
a  coloured  circle  stamped  upon  the  centre  of  the  mud 
stream,  near  its  origin,  will  move  along  with  the  mud, 
and  still  retain  its  circular  form  ;  for,  inasmuch  as  the 
velocity  of  all  points  along  the  centre  is  the  same,  there 
can  be  no  elongation  of  the  circle  longitudinally  or  trans- 
versely by  either  strain  or  pressure.  A  similar  absence 
of  longitudinal  pressure  may  exist  in  a  glacier,  and, 
where  it  exists  throughout,  no  central  structure  can,  in 
my  opinion,  be  developed. 

But  let  a  circle  be  stamped  upon  the  mud-stream  near 
its  side,  then,  when  the  mud  flows,  this  circle  will  be 
distorted  to  an  oval,  with  its  major  axis  oblique  to  the 
direction  of  motion ;  the  cause  of  this  is  that  the  portion 


MARGINAL   STRUCTURE.  383 

of  the  circle  farthest  from  the  side  of  the  canal  moves 
more  freely  than  that  adjacent  to  the  side.  The  mechani- 
cal effect  of  the  slower  lateral  motion  is  to  squeeze  the 
circle  in  one  direction,  and  draw  it  out  in  the  perpendicu- 
lar one. 

A  glance  at  Fig.  40  will  render  all  that  I  have  said  in- 
telligible. The  three  cir- 


cles  are  first  stamped  on    \  O 

the   mud  in   the   same   j  Q    > *   Q 

transverse  line  ;  but 
after  they  have  moved 
downwards  they  will  be 

in  the  same  straight  line  no  longer.  The  central  one 
will  be  the  foremost;  while  the  lateral  ones  have  their 
forms  changed  from  circles  to  ovals.  In  a  glacier  of 
the  shape  of  this  canal  exactly  similar  effects  are  pro- 
duced. Now  the  shorter  axis  m  n  of  each  oval  is  a 
line  of  squeezing  or  pressure  ;  the  longer  axis  is  a  line 
of  strain  or  tension  ;  and  the  associated  glacier  pheno- 
mena are  as  follows.  Across  the  line  m  n,  or  perpen- 
dicular to  the  pressure,  we  have  the  veined  structure 
developed,  while  across  the  line  of  tension  the  glacier  usu- 
ally breaks  and  forms  marginal  crevasses.  Mr.  Hopkins 
has  shown  that  the  lines  of  greatest  pressure  and  of  greatest 
strain  are  at  right  angles  to  each  other,  and  that  in  valleys 
of  a  uniform  width  they  enclose  an  angle  of  forty-five  de- 
grees with  the  side  of  the  glacier.  To  the  structure  thus 
formed  I  have  applied  the  term  marginal  structure.  Here, 
then,  we  see  that  there  are  mechanical  agencies  at  work  near 
the  side  of  such  a  glacier  which  are  absent  from  the  centre, 
and  we  have  effects  developed — I  believe  by  the  pressure — 
in  the  lateral  ice,  which  are  not  produced  in  the  central. 

I  have  used  the  term  "  uniform  inclination  "  in  con- 
nexion with  the  marginal  structure,  and  my  reason  for 
doing  so  will  now  appear.  In  many  glaciers  the  structure, 


384          STRUCTURE  OF  GRINDELWALD  GLACIER. 

instead  of  being  confined  to  the  margins,  sweeps  quite 
across  them.  This  is  the  case,  for  example,  on  the  Glacier 
du  Geant,  the  structure  of  which  is  prolonged  into  the 
Mer  de  Glace.  In  passing  the  strait  at  Trelaporte,  how- 
ever, the  curves  are  squeezed  and  their  apices  bruised, 
so  that  the  structure  is  thrown  into  a  state  of  confusion ; 
and  thus  upon  the  Mer  de  Glace  we  encounter  difficulty 
in  tracing  it  fairly  from  side  to  side.  Now  the  key  to  this 
transverse  structure  I  believe  to  be  the  following.  Where 
the  inclination  of  the  glacier  suddenly  $  changes  from  a 
steep  slope  to  a  gentler,  as  at  the  bases  of  the  "  cas- 
cades,"—  the  ice  to  a  certain  depth  must  be  thrown  into 
a  state  of  violent  longitudinal  compression  ;  and  along 
with  this  we  have  the  resistance  which  the  gentler  slope 
throws  athwart  the  ice  descending  from  the  steep  one. 
At  such  places  a  structure  is  developed  transverse  to 
the  axis  of  the  glacier,  and  likewise  transverse  to  the 
pressure.  The  quicker  flow  of  the  centre  causes  this 
structure  to  bend  more  and  more,  and  after  a  time  it 
sweeps  in  vast  curves  across  the  entire  glacier. 

In  illustration  of  this  point  I  will  refer,  in  the  first  place, 
to  that  tributary  of  the  Lower  Glacier  of  Grindelwald 
which  descends  from  the  Strahleck.  Walking  up  this  tri- 
butary we  come  at  length  to  the  base  of  an  ice-fall.  Let 
the  observer  here  leave  the  ice,  and  betake  himself  to 
either  side  of  the  flanking  mountain.  On  attaining  a  point 
which  commands  a  view  both  of  the  fall  and  of  the  glacier 
below  it,  an  inspection  of  the  glacier  will,  I  imagine,  solve 
to  his  satisfaction  the  case  of  structure  now  under  con- 
sideration. 

It  is  indeed  a  grand  experiment  which  Nature  here 
submits  to  our  inspection.  The  glacier  descending  from 
its  neve  reaches  the  summit  of  the  cascade,  and  is  broken 
transversely  as  it  crosses  the  brow ;  it  afterwards  descends 
the  fall  in  a  succession  of  cliffy  ice-ridges  with  transverse 


BASE  OF  CASCADE  A  "STRUCTURE  MILL."        385 

hollows  between  them.  In  these  latter  the  broken  ice  and 
debris  collect,  thus  partially  choking  the  fissures  formed 
in  the  first  instance.  Carrying  the  eye  downwards  along 
the  fall,  we  see,  as  we  approach  the  base,  these  sharp 
ridges  toned  down  ;  and  a  little  below  the  base  they  dwin- 
dle into  rounded  protuberances  which  sweep  in  curves 
quite  across  the  glacier.  At  the  base  of  the  fall  the  struc- 
ture begins  to  appear,  feebly  at  first,  but  becoming  grad- 
ually more  pronounced,  until,  at  a  short  distance  below 
the  base  of  the  fall,  the  eye  can  follow  the  fine  superficial 
groovings  from  side  to  side  ;  while  at  the  same  time  the 
ice  underneath  the  surface  has  become  laminated  in  the 
most  beautiful  manner. 

It  is  difficult  to  convey  by  writing  the  force  of  the  evi- 
dence which  the  actual  observation  of  this  natural  experi- 
ment places  before  the  mind.  The  ice  at  the  base  of  the 
fall,  retarded  by  the  gentler  inclination  of  the  valley,  has 
to  bear  the  thrust  of  the  descending  mass,  the  sudden 
change  of  inclination  producing  powerful  longitudinal 
compression.  The  protuberances  are  squeezed  more 
closely  together,  the  hollows  between  them  appear  to 
wrinkle  up  in  submission  to  the  pressure,  —  in  short,  the 
entire  aspect  of  the  glacier  suggests  the  powerful  opera- 
tions of  the  latter  force.  At  tha  place  where  it  is  exerted, 
the  veined  structure  makes  its  appearance;  and  being 
once  formed,  it  moves  downwards,  and  gives  a  character 
to  other  portions  of  the  glacier  which  had  no  share  in  its 
formation. 

An  illustration  almost  as  good,  and  equally  accessi- 
ble, is  furnished  by  the  Glacier  of  the  Rhone.  I  have 
examined  the  grand  cascade  of  this  glacier  from  both 
sides ;  and  an  ordinary  mountaineer  will  find  little  diffi- 
culty in  reaching  a  point  from  which  the  fall  and  the 
terminal  portion  of  the  glacier  are  both  distinctly  visible. 
Here  also  he  will  find  the  cliffy  ridges  separated  from 


386 


STRUCTURE  OF  RHONE  GLACIER. 


each  other  by  transverse  chasms,  becoming  more  and  more 
subdued  at  the  bottom  of  the  fall,  and  disappearing  en- 
tirely lower  down  the  glacier.  As  in  the  case  of  the 
Grindelwald  Glacier,  the  squeezing  of  the  protuberances 
arid  of  the  spaces  between  them  is  quite  apparent,  and 
where  this  squeezing  commences,  the  transverse  structure 
makes  its  appearance.  All  the  ice  that  forms  the  lower 
portion  of  this  glacier  has  to  pass  through  the  structure- 
mill  at  the  bottom  of  the  fall,  and  the  consequence  is  that 
it  is  all  laminated. 


Fig.  41. 


This  case  of  structural  development  will  be  better  appre- 
ciated on  reference  to  Figs.  41  and  42,  the  former  of  which 


*>; 


& 


TRANSVERSE  STRUCTURE.  387 

is  a  plan,  and  the  latter  a  section,  of  a  part  of  the  ice-fall 
and  of  the  glacier  below  it ;  a  b  c  f  is  the  gorge  of  the 
fall,  /  b  being  the  base.  The  transverse  cliffy  ice-ridges 
are  shown  crossing  the  cascade,  being  subdued  at  the 
base  to  protuberances  which  gradually  disappear  as  they 
advance  downwards.  The  structure  sweeps  over  the  gla- 
cier in  the  direction  of  the  fine  curved  lines ;  and  I  have 
also  endeavoured  to  show  the  direction  of  the  radial  cre- 
vasses, which,  in  the  centre  at  least,  are  at  right  angles  to 
the  veins.  To  the  manifestation  of  structure  here  con- 
sidered I  have,  for  the  sake  of  convenient  reference,  ap- 
plied the  term  transverse  structure. 

A  third  exhibition  of  the  structure  is  now  to  be  noticed. 
We  sometimes  find  it  in  the  middle  of  a  glacier  and  run- 
ning parallel  to  its  length.  On  the  centre  of  the  ice-fall 
of  the  Talefre,  for  example,  we  have  a  structure  of  this 
kind,  which  preserves  itself  parallel  to  the  axis  of  the  fall 
from  top  to  bottom.  But  we  discover  its  origin  higher  up. 
The  structure  here  has  been  produced  at  the  extremity 
of  the  Jardin,  where  the  divided  ice  meets,  and  not  only 
brings  into  partial  parallelism  the  veins  previously  exist- 
ing along  the  sides  of  the  Jardin,  but  develops  them  still 
further  by  the  mutual  pressure  of  the  portions  of  newly 
welded  ice.  Where  two  tributary  glaciers  unite,  this  is 
perhaps  without  exception  the  case.  Underneath  the  mo- 
raine formed  by  the  junction  of  the  Talefre  and  Lechaud 
the  structure  is  finely  developed,  and  the  veins  run  in  the 
direction  of  the  moraine.  The  same  is  true  of  the  ice 
under  the  moraine  formed  by  the  junction  of  the  Le*chaud 
and  Ge*ant.  These  afterwards  form  the  great  medial  mo- 
raines of  the  Mer  de  Glace,  and  hence  the  structure  of 
the  trunk-stream  underneath  these  moraines  is  parallel  to 
the  direction  of  the  glacier.  This  is  also  true  of  the  sys- 
tem of  moraines  formed  by  the  glaciers  of  Monte  Rosa. 
It  is  true  in  an  especial  manner  of  the  lower  glacier  of 


888 


LONGITUDINAL  STRUCTURE. 


the  Aar,  whose  medial  moraine  perhaps  attains  grander 
proportions  than  any  other  in  the  Alps,  and  underneath 
which  the  structure  is  finely  developed. 

The  manner  in  which  I  have  illustrated  the  production 
of  this  structure  will  be  understood  from  Fig.  43.     B  B' 

are  two  wooden  box- 
es, communicating 
by  sluice-fronts  with 
two  branch  canals, 
which  unite  to  a 
common  trunk  at  G. 
They  are  intended 
to  represent  respec- 
tively the  trunk  and 
tributaries  of  the  Un- 
teraar  Glacier,  the 
part  G  being  the  Ab- 
schwung,  where  the 
Lauteraar  and  Fin- 
steraar  glaciers  unite 
to  form  the  Unteraar. 
The  mud  is  first  per- 
mitted to  flow  beneath  the  two  sluices  until  it  has  cov- 
ered the  bottom  of  the  trough  for  some  'distance,  when  it 
is  arrested.  The  end  of  a  glass  tube  is  then  dipped  into 
a  mixture  of  rouge  and  water,  and  small  circles  are 
stamped  upon  the  mud.  The  two  branches  are  thickly 
covered  with  these  circles.  The  sluices  being  again  raised, 
the  mud  in  the  branches  moves  downwards,  carrying  with 
it  the  circles  stamped  upon  it ;  and  the  manner  in  which 
these  circles  are  distorted  enables  us  to  infer  the  strains 
and  pressures  to  which  the  'mud  is  subjected  during  its 
descent.  The  figure  represents  approximately  what  takes 
place.  The  side-circles,  as  might  be  expected,  are  squeezed 
to  oblique  ovals,  but  it  is  at  the  junction  of  the  branches 


Fig.  43. 


EFFORTS   TO   SOLVE   QUESTION.  389 

that  the  chief  effect  of  pressure  is  produced.  Here,  by 
the  mutual  thrust  of  the  branches,  the  circles  are  not  only 
changed  to  elongated  ellipses,  but  even  squeezed  to  straight 
lines.  In  the  case  of  the  glacier  this  is  the  region  at  which 
the  structure  receives  its  main  development.  To  this 
manifestation  of  the  veins  1  have  applied  the  term  longi- 
tudinal structure. 

The  three  main*  sources  of  the  blue  veins  are,  I  think, 
here  noted ;  but  besides  these  there  are  many  local  causes 
which  influence  their  production.  I  have  seen  them  well 
formed  where  a  glacier  is  opposed  by  the  sudden  bend  of 
a  valley,  or  by  a  local  promontory  which  presents  an  ob- 
stacle sufficient  to  bring  the  requisite  pressure  into  play. 
In  the  glaciers  of  the  Tyrol  and  of  the  Oberland  I  have 
seen  examples  of  this  kind  ;  but  the  three  principal 
sources  of  the  veins  are,  I  think,  those  stated  above. 

It  was  long  before  I  cleared  my  mind  of  doubt  regard- 
ing the  origin  of  the  lamination.  When  on  the  Mer  de 
Glace  in  1857  I  spared  neither  risk  nor  labour  to  instruct 
myself  regarding  it.  I  explored  the  Talefre  basin,  its 
cascade,  and  the  ice  beneath  it.  Several  days  were  spent 
amid  the  ice  humps  and  cliffs  at  the  lower  portion  of  the 
fall.  I  suppose  I  traversed  the  Glacier  du  Gdant  twenty 
times,  and  passed  eight  or  ten  days  amid  the  confusion  of 
its  great  cascade.  I  visite'd  those  places  where,  it  had 
been  affirmed,  the  veins  were  produced.  I  endeavoured 
to  satisfy  myself  of  the  mutability  which  had  been  as- 
cribed to  them  ;  but  a  close  examination  reduced  the 
value  of  each  particular  case  so  much,  that  I  quitted  the 
glacier  that  year  with  nothing  more  than  an  opinion  that 
the  structure  and  the  stratification  were  two  different 
things.  I,  however,  drew  up  a  statement  of  the  facts 
observed,  with  the  view  of  presenting  it  to  the  Royal 
Society ;  but  I  afterwards  felt  that  in  thus  acting  I  should 
merely  swell  the  literature  of  the  subject  without  adding 


390  EXPEDITION  FOR  THIS  PURPOSE. 

anything  certain.  I  therefore  withheld  the  paper,  and 
resolved  to  devote  another  year  to  a  search  among  the 
chief  glaciers  of  the  Oberland,  of  the  Canton  Valais,  and 
of  Savoy,  for  proofs  which  should  relieve  my  mind  of  all 
doubt  upon  the  subject. 

Accordingly  in  1858  I  visited  the  glaciers  of  Rosenlaui, 
Schwartzwald,  Grindelwald,  the  Aar,  the  Rhone,  and  the 
Aletsch,  to  the  examination  of  which  latter  I  devoted 
more  than  a  week.  I  afterward  went  to  Zermatt,  and, 
taking  up  my  quarters  at  the  Riffelberg,  devoted  eleven 
days  to  the  examination  of  the  great  system  of  glaciers 
of  Monte  Rosa.  I  explored  the  Gorner  glacier  up  almost 
to  the  Cima  de  Jazzi ;  and  believed  that  in  it  I  could 
trace  the  structure  from  portions  of  the  glacier  where  it 
vanished,  through  various  stages  of  perfection,  up  to  its 
full  development.  I  believe  this  still ;  but  yet  it  is  noth- 
ing but  a  belief,  which  the  utmost  labour  that  I  could 
bestow  did  not  raise  to  a  certainty.  The  Western  glacier 
of  Monte  Rosa,  the  Schwartze  glacier,  the  Trifti  glacier, 
the  glacier  of  the  little  Mont  Cervin,  and  of  St.  Theodule, 
were  all  examined  in  connexion  with  the  great  trunk- 
stream  of  the  Gorner,  to  which  they  weld  themselves  ; 
and  though  the  more  1  pursued  the  subject,  the  stronger 
my  conviction  became  that  pressure  was  the  cause  of  the 
structure,  a  crucial  case  was  still  wanting. 

In  the  phenomena  of  slaty  cleavage,  it  is  often,  if  not 
usually,  found  that  the  true  cleavage  cuts  the  planes  of 
stratification,  —  sometimes  at  a  very  high  angle.  Had  this 
not  been  proved  by  the  observations  of  Sedgwick  and 
others,  geologists  would  not  have  been  able  to  conclude 
that  cleavage  and  bedding  were  two  different  things,  and 
needed  wholly  different  explanations.  My  aim,  throughout 
the  expedition  of  1858,  was  to  discover  in  the  ice  a  parallel 
case  to  the  above ;  to  find  a  clear  and  undoubted  instance 
where  the  veins  and  the  stratification  were  simultaneously 


CASE   OF  STRUCTURE  ON  THE  ALETSCH. 


391 


exhibited,  cutting  each  other  at  an  unmistakable  angle. 
On  the  6th  of  August,  while  engaged  with  Professor 
Ramsay  upon  the  Great  Aletsch  Glacier,  not  far  from 
its  junction  with  the  Middle  Aletsch,  I  observed  what 
appeared  to  me  to  be  the  lines  of  bedding  running  nearly 
horizontal  along  the  wall  of  a  great  crevasse,  while  cutting 
them  at  a  large  angle  was  the  true  veined  structure.  I 
drew  my  friend's  attention  to  the  fact,  and  to  him  it  ap- 
peared perfectly  conclusive.  It  is  from  a  sketch  made  by 
him  at  the  place  that  Fig.  44  has  been  taken. 


rm 


Fig.  44. 

This  was  the  only  case  of  the  kind  which  I  observed 
upon  the  Aletsch  Glacier  ;  and  as  I  afterwards  spent  day 
after  day  upon  the  Monte  Rosa  glaciers,  vainly  seeking 
a  similar  instance,  the  thought  again  haunted  me  that  we 
might  have  been  mistaken  upon  the  Aletsch.  In  this 
state  of  mind  I  remained  until  the  18th  of  August,  a  day 
devoted  to  the  examination  of  the  Furgge  Glacier,  which 
lies  at  the  base  of  the  Mont  Cervin. 

Crossing  the  valley  of  the  Gorner  Glacier,  and  taking  a 
plunge  as  I  passed  into  the  Schwarze  See,  I  reached,  in 
good  time,  the  object  of  my  day's  excursion.  Walking  up 
the  glacier,  I  at  length  found  myself  opposed  by  a  frozen 
cascade  composed  of  four  high  terraces  of  ice.  The 
highest  of  these  was  chiefly  composed  of  ice-cliffs  and 


392  STRUCTURE   OF  THE   FURGGE  GLACIER. 


cSj  many  of  which  had  fallen,  and  now  stood  like 
rocking  stones  upon  the  edge  of  the  second  terrace.  The 
glacier  at  the  base  of  the  cascade  was  strewn  with  broken 
ice,  and  some  blocks  two  hundred  cubic  feet  in  volume 
had  been  cast  to  a  considerable  distance  down  the  glacier. 

Upon  the  faces  of  the  terraces  the  stratification  of  the 
neve  was  most  beautifully  shown,  running  in  parallel 
and  horizontal  lines  along  the  weathered  surface.  The 
snow-field  above  the  cascade  is  a  frozen  plain,  smooth 
almost  as  a  sheltered  lake.  The  successive  snow-falls  de- 
posit themselves  with  great  regularity,  and  at  the  summit 
of  the  cascade  the  sections  of  the  neve  are  for  the  first 
time  exposed.  Hence  their  peculiar  beauty  and  definition. 

Indeed  the  figure  of  a  lake  pouring  itself  over  a  rocky 
barrier  which  curves  convexly  upwards,  thus  causing  the 
water  to  fall  down  it,  not  only  longitudinally  over  the 
vertex  of  the  curve,  but  laterally  over  its  two  arms,  will 
convey  a  tolerably  correct  conception  of  the  shape  of  the 
fall.  Towards  the  centre  the  ice  was  powerfully  squeezed 
laterally,  the  beds  were  bent,  and  their  continuity  often 
broken  by  faults.  On  inspecting  the  ice  from  a  distance 
with  my  opera-glass,  I  thought  I  saw  structural  groovings 
cutting  the  strata  at  almost  a  right  angle.  Had  the  ques- 
tion been  an  undisputed  one,  I  should  perhaps  have  felt 
so  sure  of  this  as  not  to  incur  the  danger  of  pushing  the 
inquiry  further  ;  but,  under  the  circumstances,  danger 
was  a  secondary  point.  Resigning,  therefore,  my  glas^s 
to  my  guide,  who  was  to  watch  the  tottering  blocks  over- 
head, and  give  me  warning  should  they  move,  I  advanced 
to  the  base  of  the  fall,  removed  with  my  hatchet  the 
weathered  surface  of  the  ice,  and  found  underneath  it  the 
true  veined  structure,  cutting,  at  nearly  a  right  angle,  the 
planes  of  stratification.  The  superficial  groovings  were 
not  uniformly  distributed  over  the  fall,  but  appeared  most 
decided  at  those  places  where  the  ice  appeared  to  have 


ICE   TERRACE  EXAMINED.  893 


394 


LAMINATION  AND   STRATIFICATION. 


preceded  me  in  this  observation,  and  hence  my  results  are 
to  be  taken  as  mere  confirmations  of  his. 

Fig.  45  represents  a  crum- 
pled portion  of  the  ice,  with 
the  lines  of  lamination  pass- 
ing through  the  strata.    Fig. 
(V    46  represents  a  case  where 
!—    a   fault   had   occurred,   the 
veins  at  both  sides   of  the 
line  of  dislocation  being  inclined  towards  each  other. 


Fig.  46. 


DIFFERENTIAL  MOTION  GREATEST  AT  EDGES.    395 


THE   VEINED   STRUCTURE   AND  THE   DIF- 
FERENTIAL MOTION. 

(28.) 

I  HAVE  now  to  examine  briefly  the  explanation  of  the 
structure  which  refers  it  to  differential  motion, — to  a  slid- 
ing of  the  particles  of  ice  past  each  other,  which  leaves  the 
traces  of  its  existence  in  the  blue  veins.  The  fact  is  em- 
phatically dwelt  upon  by  those  who  hold  this  view,  that 
the  structure  is  best  developed  nearest  to  the  sides  of  the 
glacier,  where  the  differential  motion  is  greatest.  Why 
the  differential  motion  is  at  its  maximum  near  to  the 
sides  is  easily  understood.  Let  A  B, 
CD,  Fig.  47,  represent  the  two  sides 
of  a  glacier,  moving  in  the  direction  of 
the  arrow,  and  let  m  a  b  c  n  be  a 
straight  line  of  stakes  set  out  across 
the  glacier  to-day.  Six  months  hence 
this  line,  by  the  motion  of  the  ice 
downwards,  will  be  bent  to  the  form 
m  a1  b1  c'  n:  this  curve  will  not  be  cir- 
cular, it  will  be  flattened  in  the  middle  ; 
the  points  a  and  c,  at  some  distance 
on  each  side  of  the  centre  £,  move  in 
fact  with  nearly  the  same  velocity  as  the  centre  itself. 
Not  so  with  the  sides :  —  a1  and  c1  have  moved  considera- 
bly in  advance  of  m  and  n,  and  hence  we  say  that  the 
difference  of  motion,  or  the  differential  motion,  of  the  par- 
ticles of  ice  near  to  the  side  is  a  maximum. 

During  all  this  time  the  points  m  a'  b'  c'  n  have  been 
moving  straight  down  the  glacier ;  and  hence  it  will  be 
understood  that  the  sliding  of  the  parts  past  each  other, 


Fig.  47. 


396  STRUCTURE   OBLIQUE   TO   SIDES. 

or,  in  other  words,  the  differential  motion,  is  parallel  to  the 
sides  of  the  glacier.  This,  indeed,  is  the  only  differential 
motion  that  experiment  has  ever  established ;  and  conse- 
quently, when  we  find  the  best  blue  veins  referred  to 
the  sides  of  the  glacier  because  the  differential  motion  is 
there  greatest,  we  naturally  infer  that  the  motion  meant 
is  parallel  to  the  sides. 

But  the  fact  is,  that  this  motion  would  not  at  all  account 
for  the  blue  veins,  for  they  are  not  parallel  to  the  sides, 
.but  oblique  to  them.  This  difficulty  revealed  itself  after  a 
time  to  those  who  first  propounded  the  theory  of  differen- 
tial motion,  and  caused  them  to  modify  their  explanation 
of  the  structure.  Differential  motion  is  still  assumed  to  be 
the  cause  of  the  veins,  but  now  a  motion  is  meant  oblique  to 
the  sides,  and  it  is  supposed  to  be  obtained  in  the  follow- 
ing way :  —  Through  the  quicker  motion  of  the  point  c' 
the  ice  between  it  and  n  becomes  distended ;  that  is  to 
say,  the  line  c'n  is  in  a  state  of  strain,  —  there  is  a  drag, 
it  is  said,  oblique  to  the  sides  of  the  glacier ;  and  it 
is  therefore  in  this  direction  that  the  particles  will  be 
caused  to  slide  past  each  other.  Dr.  Whewell,  who  ad- 
vocates this  view,  thus  expounds  it.  He  supposes  the  case 
of  an  alpine  valley  filled  with  India-rubber  which  has  been 
warmed  until  it  has  partially  melted,  or  become  viscous,  and 
then  asks,  "  What  will  now  be  the  condition  of  the  mass  ? 
The  sides  and  bottom  will  still  be  held  back  by  the  fric- 
tion ;  the  middle  and  upper  part  will  slide  forwards,  but  not 
freely.  This  want  of  freedom  in  the  motion  (arising  from 
the  viscosity)  will  produce  a  drag  towards  the  middle  of 
the  valley,  where  the  motion  is  freest ;  hence  the  direction 
in  which  the  filaments  slide  past  each  other  will  be  ob- 
liquely directed  towards  the  middle.  The  sliding  will 
separate  the  mass  according  to  such  lines ;  and  though  new 
attachments  will  take  place,  the  mass  may  be  expected  to 
retain  the  results  of  this  separation  in  the  traces  of  parallel 


STRUCTURE   CROSSES  LINES   OF  SLIDING.         397 

fissures."  *  Nothing  can  be  clearer  than  the  image  of 
the  process  thus  placed  before  the  mind's  eye. 

One  fact  of  especial  importance  is  to  be  borne  in  mind  : 
the  sliding  of  filaments  which  is  thus  supposed  to  take 
place  oblique  to  the  glacier  has  never  been  proved  ;  it  is 
wholly  assumed.  A  moraine,  it  is  admitted,  will  run 
parallel  to  the  side  of  a  glacier,  or  a  block  will  move  in 
the  same  direction  from  beginning  to  end,  without  being 
sensibly  drawn  towards  the  centre,  but  still  it  is  supposed 
that  the  sliding  of  parts  exists,  though  of  a  character  so 
small  as  to  render  it  insensible  to  measurement. 

My  chief  difficulty  as  regards  this  theory  may  be  ex- 
pressed in  a  very  few  words.  If  the  structure  be  pro- 
duced by  differential  motion,  why  is  the  large  and  real 
differential  motion  which  experiments  have  established 
incompetent  to  produce  it  ?  And  how  can  the  veins  run, 
as  they  are  admitted  to  do,  across  the  lines  of  maximum 
sliding  from  their  origin  throughout  the  glacier  to  its 
end  ? 

That  a  drag  towards  the  centre  of  the  glacier  exists,  is 
undeniable,  but  that  in  consequence  of  the  drag  there  is 
a  sliding  of  filaments  in  this  direction,  is  quite  another 
thing.  I  have  in  another  place  f  endeavoured  to  show 
experimentally  that  no  such  sliding  takes  place,  that  the 
drag  on  any  point  towards  the  centre  expresses  only  half 
the  conditions  of  the  problem ;  being  exactly  neutralized 
by  the  thrust  towards  the  sides.  It  has  been,  moreover, 
shown  by  Mr.  Hopkins,  that  the  lines  of  maximum  strain 
and  of  maximum  sliding  cannot  coincide  ;  indeed,  if  all 
the  particles  be  urged  by  the  same  force,  no  matter  how 
strong  the  pull  may  be,  there  will  be  no  tendency  of  one 
to  slide  past  the  other. 

*  "Philosophical  Magazine,"  Ser.  III.  vol.  xxvi. 

t  "  Proceedings  of  the  Royal  Institution,"  vol.  ii.  p.  324. 


398  THEOKY  STATED. 


THE    RIPPLE-THEORY    OF    THE    VEINED 
STRUCTURE. 

(29.) 

THE  assumption  of  oblique  sliding,  and  the  production 
thereby  of  the  marginal  structure,  have,  however,  been 
fortified  by  considerations  of  an  ingenious  and  very  in- 
teresting kind.  "  How,"  I  have  asked,  "  can  the  oblique 
structure  persist  across  the  lines  of  greatest  differential 
motion  throughout  the  length  of  the  glacier  ?  "  But  here 
I  am  met  by  another  question  which  at  first  sight  might 
seem  equally  unanswerable,  —  "  How  do  ripple-marks  on 
the  surface  of  a  flowing  river,  which  are  nothing  else  than 
lines  of  differential  motion  of  a  low  order,  cross  the  river 
from  the  sides  obliquely,  while  the  direction  of  greatest 
differential  motion  is  parallel  to  the  sides  ?  "  If  I  un- 
derstand aright,  this  is  the  main  argument  of  Professor 
Forbes  in  favour  of  his  theory  of  the  oblique  marginal 
structure.  It  is  first  introduced  in  a  note  at  page  378 
of  his  "  Travels ; "  he  alludes  to  it  in  a  letter  written 
the  following  year ;  in  his  paper  in  the  "  Philosophical 
Transactions "  he  develops  the  theory.  He  there  gives 
drawings  of  ripple-marks  observed  in  smooth  gutters  after 
rain,  and  which  he  finds  to  be  inclined  to  the  course  of 
the  stream,  exactly  as  the  marginal  structure  is  inclined 
to  the  side  of  the  glacier.  The  explanation  also  em- 
braces the  case  of  an  obstacle  placed  in  the  centre  of  a 
river.  "  A  case,"  writes  Professor  Forbes,  "  parallel  to 
the  last  mentioned,  where  a  fixed  obstacle  cleaves  a  de- 
scending stream,  and  leaves  its  trace  in  the  fan-shaped 
tail,  is  well  known  in  several  glaciers,  as  in  that  at  Fer- 
pecle,  and  the  Glacier  de  Lys  on  the  south  side  of  Monte 
Rosa ;  particularly  the  last,  where  the  veined  structure 


THEOEY  EXAMINED.  399 

follows  the  law  just  mentioned."  In  his  Twelfth  Letter 
he  also  refers  to  the  ripples  "  as  exactly  corresponding  to 
the  position  of  the  icy  bands."  In  his  letter  to  Dr.  Whe- 
well,  published  in  the  "  Occasional  Papers,"  page  58,  he 
writes  as  follows  :  —  "  The  same  is  remarkably  shown  in 
the  case  of  a  stream  of  water,  for  instance,  a  mill-race. 
Although  the  movement  of  the  water,  as  shown  by  float- 
ing bodies,  is  exceedingly  nearly  (for  small  velocities  sen- 
sibly) parallel  to  the  sides,  yet  the  variation  of  the  speedw 
from  the  side  to  the  centre  of  the  stream  occasions  a  rip- 
ple, or  molecular  discontinuity,  which  inclines  forwards 
from  the  sides  to  the  centre  of  the  stream  at  an  angle 
with  the  axis  depending  on  the  ratio  of  the  central  and 
lateral  velocity.  The  veined  structure  of  the  ice  corre- 
sponds to  the  ripple  of  the  water,  a  molecular  discontinu- 
ity whose  measure  is  not  comparable  to  the  actual  velocity 
of  the  ice  ;  and  therefore  the  general  movement  of  the 
glacier,  as  indicated  by  the  moraines,  remains  sensibly 
parallel  to  the  sides."  This  theory  opens  up  to  us  a 
series  of  interesting  and  novel  considerations  which  I 
think  will  repay  the  reader's  attention.  If  the  ripples 
in  the  water  and  the  veins  in  the  ice  be  due  to  the  same 
mechanical  cause,  when  we  develop  clearly  the  origin  of 
the  former  we  are  led  directly  to  the  explanation  of  the 
latter.  I  shall  now  endeavour  to  reduce  the  ripples  to 
their  mechanical  elements. 

The  Messrs.  Weber  have  described  in  their  "  Wellen- 
lehre  "  an  effect  of  wave-motion  which  it  is  very  easy  to 
obtain.  When  a  boat  moves  through  perfectly  smooth 
water^  and  the  rower  raises  his  oar  out  of  the  water,  drops 
trickle  from  its  blade,  and  each  drop  where  it  falls  pro- 
duces a  system  of  concentric  rings.  The  circular  waves 
as  they  widen  become  depressed,  and,  if  the  drops  suc- 
ceed each  other  with  sufficient  speed,  the  rings  cross  each 
other  at  innumerable  points.  The  effect  of  this  is  to  blot 


400 


RIPPLES  DEDUCED  FROM  RINGS. 


out  more  or  less  completely  all  the  circles,  and  to  leave 
behind  two  straight  divergent  ripple-lines,  which  are 
tangents  to  all  the  external  rings  ;  being  in  fact  formed 
by  the  intersection  of  the  latter,  as  a  caustic  in  optics  is 
formed  by  the  intersection  of  luminous  rays.  Fig.  48, 


Fig.  48. 

which  is  virtually  copied  from  M.  Weber,  will  render 
this  description  at  once  intelligible.  The  boat  is  sup- 
posed to  move  in  the  direction  of  the  arrow,  and  as  it 
does  so  the  rings  which  it  leaves  behind  widen,  and  pro- 
duce the  divergence  of  the  two  straight  resultant  lines 
of  ripple. 

The  more  quickly  the  drops  succeed  each  other,  the 
more  frequent  will  be  the  intersections  of  the  rings  ;  but 
as  the  speed  of  succession  augments,  we  approach  the 
case  of  a  continuous  vein  of  liquid ;  and  if  we  suppose 
the  continuity  to  be  perfectly  established,  the  ripples  will 
still  be  produced. with  a  smooth  space  between  them  as 
before.  This  experiment  may  indeed  be  made  with  a 
well-wetted  oar,  which  on  its  first  emergence  from  the 
water  sends  into  it  a  continuous  liquid  vein.  The  same 
effect  is  produced  when  we  substitute  for  the  stream  of 
liquid  a  solid  rod,  —  a  common  walking-stick  for  exam- 
ple. A  water-fowl  swimming  in  calm  water  produces 
-two  divergent  lines  of  ripples  of  a  similar  kind. 

We  have  here  supposed  the  water  of  the  lake  to  be  at 


MEASURE   OF  DIVERGENCE  OF  RIPPLES.  401 

rest,  and  the  liquid  vein  or  the  solid  rod  to  move  through 
it ;  but  precisely  the  same  effect  is  produced  if  we  suppose 
the  rod  at  rest  and  the  liquid  in  motion.  Let  a  post,  for 
example,  be  fixed  in  the  middle  of  a  flowing  river;  diverg- 
ing from  that  post  right  and  left  we  shall  have  lines  of 
ripples,  exactly  as  if  the  liquid  were  at  rest  and  the  post 
moved  through  it  with  the  velocity  of  the  river.  If  the 
same  post  be  placed  close  to  the  bank,  so  that  one  of  its 
edges  only  shall  act  upon  the  water,  diverging  from  that 
edge  we  shall  have  a  single  line  of  ripples  which  will  cross 
the  river  obliquely  towards  its  centre.  It  is  manifest  that 
any  other  obstacle  will  produce  the  same  effect  as  our 
hypothetical  post.  In  the  words  of  Professor  Forbes,  "  the 
slightest  prominence  of  any  kind  in  the  wall  of  such  a 
conduit,  a  bit  of  wood  or  a  tuft  of  grass,  is  sufficient  to 
produce  a  well-marked  ripple-streak  from  the  side  towards 
the  centre." 

The  foregoing  considerations  show  that  the  divergence 
of  the  two  lines  of  ripples  from  the  central  post,  and  of 
the  single  line  in  the  case  of  the  lateral  post,  have  their 
mechanical  element,  if  I  may  use  the  term,  in  the  experi- 
ment of  the  Messrs.  Weber.  In  the  case  of  a  swimming 
duck  the  connexion  between  the  diverging  lines  of  rip- 
ples and  the  propagation  of  rings  round  a  disturbed  point 
is  often  very  prettily  shown.  When  the  creature  swims 
with  vigour  the  little  foot  with  which  it  strikes  the  water 
often  comes  sufficiently  near  to  the  surface  to  produce 
an  elevation,  —  sometimes  indeed  emerging  from  the 
water  altogether.  Round  the  point  thus  disturbed  rings 
are  immediately  propagated,  and  the  widening  of  those 
rings  is  the  exact  measure  of  the  divergence  of  the  ripple 
lines.  The  rings  never  cross  the  lines ;  —  the  lines  never 
retreat  from  the  rings. 

If  we  compare  the  mechanical  actions  here  traced  out 
with  those  which  take  place  upon  a  glacier,  I  think  it  will 


402    KIPPLES  AND  VEINS  DUE  TO  DIFFERENT  CAUSES. 

be  seen  that  the  analogy  between  the  ripples  and  the 
veined  structure  is  entirely  superficial.  How  the  struc- 
ture ascribed  to  the  Glacier  de  Lys  is  to  be  explained  I 
do  not  know,  for  I  have  never  seen  it ;  but  it  seems  impos- 
sible that  it  could  be  produced,  as  ripples  are,  by  a  fixed 
obstacle  which  "  cleaves  a  descending  stream."  No  one 
surely  will  affirm  that  glacier-ice  so  closely  resembles  a 
fluid  as  to  be  capable  of  transmitting  undulations,  as  water 
propagates  rings  round  a  disturbed  point.  The  difficulty 
of  such  a  supposition  would  be  augmented  by  taking  into 
account  the  motion  of  the  individual  liquid  particles  which 
go  to  form  a  ripple  ;  for  the  Messrs.  Weber  have  shown 
that  these  move  in  closed  curves,  describing  orbits  more 
or  less  circular.  Can  it  be  supposed  that  the  particles  of 
ice  execute  a  motion  of  this  kind  ?  If  so,  their  orbital 
motions  may  be  easily  calculated,  being  deducible  from 
the  motion  of  the  glacier  compounded  with  the  inclination 
of  the  veins.  If  so  important  a  result  could  be  established, 
all  glacier  theories  would  vanish  in  comparison  with  it. 

There  is  another  interesting  point  involved  in  the  pas- 
sage above  quoted.  Professor  Forbes  considers  that  the 
ripple  is  occasioned  by  the  variation  of  speed  from  the  side 
to  the  centre  of  the  stream,  and  that  its  inclination  depends 
on  the  ratio  of  the  central  and  lateral  velocity.  If  I  am 
correct  in  the  above  analysis,  this  cannot  be  the  case.  The 
inclination  of  the  ripple  depends  solely  on  the  ratio  of  the 
rivers  translatory  motion  to  the  velocity  of  its  wave-mo- 
tion. Were  the  lateral  and  central  velocities  alike,  a  mo- 
mentary disturbance  at  the  side  would  produce  a  straight 
ripple-mark,  whose  inclination  would  be  compounded  of 
the  two  elements  just  mentioned.  If  the  motion  of  the 
water  vary  from  side  to  centre,  the  velocity  of  wave-pro- 
pagation remaining  constant,  the  inclination  of  the  ripple 
will  also  vary,  that  is  to  say,  we  shall  have  a  curved  ripple 
instead  of  a  straight  one.  This,  of  course,  is  the  case  which 


POSITION  OF  RIPPLES  NOT  THAT  OF  STRUCTURE.     408 

we  find  in  Nature,  but  the  curvature  of  such  ripples  is 
totally  different  from  that  of  the  veined  structure.  Owing 
to  the  quicker  translator/  movement,  the  ripples,  as  they 
approach  the  centre,  tend  more  to  parallelism  with  the 
direction  of  the  river ;  and  after  having  passed  the  centre, 
and  reached  the  slower  water  near  the  opposite  side,  their 
inclination  to  the  axis  gradually  augments.  Thus  the 
ripples  from  the  two  sides  form  a  pair  of  symmetric 
curves,  which  cross  each  other  at  the  centre,  and  possess 
the  form  a ob,  cod,  shown  in  Fig.  49.  A  similar  pair 


Fig.  49. 


of  curves  would  be  produced  by  the  reflection  of  these. 
Knowing  the  variation  of  motion  from  side  to  centre, 
any  competent  mathematician  could  find  the  question  of 
the  ripple-curves  ;  but  it  would  be  out  of  place  for  me  to 
attempt  it  here. 


404      POSSIBLE  EXPERIMENT  WITH  GLASS  PRISM. 


THE  VEINED  STRUCTURE  AND  PRESSURE. 
(30.) 

IF  a  prism  of  glass  be  pressed  by  a  sufficient  weight, 
the  particles  in  the  line  of  pressure  will  be  squeezed  more 
closely  together,  while  those  at  right  angles  to  this  line 
will  be  forced  further  apart.  The  existence  of  this  state  of 
strain  may  be  demonstrated  by  the  action  of  such  squeezed 
glass  upon  polarised  light.  It  gives  rise  to  colours,  and 
it  is  even  possible  to  infer  from  the  tint  the  precise  amount 
of  pressure  to  which  the  glass  is  subjected.  M.  Wertheim 
indeed  has  most  ably  applied  these  facts  to  the  construc- 
tion of  a  dynamometer,  or  instrument  for  measuring  pres- 
sures, exceeding  in  accuracy  any  hitherto  devised. 

When  the  pressure  applied  becomes  too  great  for  the 
glass  to  sustain,  it  flies  to  pieces.  But  let  us  suppose  the 
sides  of  the  prism  defended  by  an  extremely  strong  jack- 
et, in  which  the  prism  rests  like  a  closely-fitting  plug,  and 
which  yields  only  when  a  pressure  more  than  sufficient  to 
crush  the  glass  is  applied.  Let  the  pressure  be  gradually 
augmented  until  this  point  is  attained  ;  afterwards  both 
the  glass  and  its  jacket  will  shorten  and  widen  ;  the  jacket 
will  yield  laterally,  being  pushed  out  with  extreme  slow- 
ness by  the  glass  within. 

Now  I  believe  that  it  would  be  possible  to  make  this  ex- 
periment in  such  a  manner  that  the  glass  should  be  flat- 
tened, partly  through  rupture,  and  partly  through  lateral 
molecular  yielding ;  the  prism  would  change  its  form,  and 
yet  present  a  firmly  coherent  mass  when  removed  from  its 
jacket.  I  have  never  made  the  experiment ;  nobody  has, 
as  far  as  I  know  ;  but  experiments  of  this  kind  are  often 
made  by  Nature.  In  the  Museum  of  the  Government 


POSSIBLE   EXPERIMENT   WITH  PRISM  OF   ICE.      405 

School  of  Mines,  for  example,  we  have  a  collection  of 
quartz  stones  placed  there  by  Mr.  Salter,  and  which  have 
been  subjected  to  enormous  pressure  in  the  neighbour- 
hood of  a  fault.  These  rigid  pebbles  have,  in  some  cases, 
been  squeezed  against  each  other  so  as  to  produce  mutual 
flattening  and  indentation.  Some  of  them  have  yielded 
along  planes  passing  through  them,  as  if  one-half  had 
slidden  over  the  other  ;  but  the  reattachment  is  very 
strong.  Some  of  the  larger  stones,  moreover,  which  have 
endured  pressure  at  a  particular  point,  are  fissured  ra- 
dially around  this  point.  In  short,  the  whole  collection 
is  a  most  instructive  example  of  the  manner  and  extent 
to  which  one  of  the  most  rigid  substances  in  nature  can 
yield  on  the  application  of  a  sufficient  force. 

Let  a  prism  of  ice  at  32°  be  placed  in  a  similar  jacket 
to  that  which  we  have  supposed  to  envelop  the  glass  prism. 
The  ice  yields  to  the  pressure  with  incomparably  greater 
ease  than  the  glass ;  and  if  the  force  be  slowly  applied, 
the  lateral  yielding  will  far  more  closely  resemble  that  of 
a  truly  plastic  body.  Supposing  such  a  piece  of  ice  to  be 
filled  with  numerous  small  air-bubbles,  the  tendency  of  the 
pressure  would  be  to  flatten  these  bubbles,  and  to  squeeze 
them  out  of  the  ice.  Were  the  substance  perfectly  homo- 
geneous, this  flattening  and  expulsion  would  take  place 
uniformly  throughout  its  entire  mass  ;  but  I  believe  there 
is  no  such  homogeneous  substance  in  nature  ;  —  the  ice 
will  yield  at  different  places,  leaving  between  them  spaces 
which  are  comparatively  unaffected  by  the  pressure.  From 
the  former  spaces  the  air-bubbles  will  be  more  effectually 
expelled  ;  and  I  have  no  doubt  that  the  result  of  such 
pressure  acting  upon  ice  so  protected  would  be  to  produce 
a  laminated  structure  somewhat  similar  to  that  which  it 
produces  in  those  bodies  which  exhibit  slaty  cleavage. 

I  also  think  it  certain  that,  in  this  lateral  displace- 
ment of  the  particles,  these  must  move  past  each  other. 


406  LAMINATION  PRODUCED  BY  PRESSURE. 

This  is  an  idea  which  I  have  long  entertained,  as  the  fol- 
lowing passage  taken  from  the  paper  published  by  Mr. 
Huxley  and  myself  will  prove: — "Three  principal  causes 
may  operate  in  producing  cleavage  :  first,  the  reducing  of 
surfaces  of  weak  cohesion  to  parallel  planes  ;  second,  the 
flattening  of  minute  cavities  ;  and  third,  the  weakening 
of  cohesion  by  tangential  action.     The  third  action  is  ex- 
emplified by  the  state  of  the  rails 'near  a  station  where  a 
break  is  habitually  applied  to  a  locomotive.     In  this  case, 
while  the  weight  of  the  train  presses  vertically,  its  motion 
tends  to  cause  longitudinal  sliding  of  the  particles  of  the 
rail.     Tangential  action  does  not,  however,  necessarily 
imply  a  force  of  the  latter  kind.     When  a  solid  cylinder 
an  inch  in  height  is  squeezed  to  a  vertical  cake  a  quarter 
of  an  inch  in  height,  it  is  impossible,  physically  speaking, 
that  the  particles  situated  in  the  same  vertical  line  shall 
move  laterally  with  the  same  velocity ;  but  if  they  do  not, 
the  cohesion  between  them  will  be  weakened  or  ruptured. 
The  pressure,  however,  will  produce  new  contact ;  and  if 
this  have  a  cohesive  value  equal  to  that  of  the  old  con- 
tact, no  cleavage  from  this  cause  can  arise.     The  relative 
capacities  of  different  substances  for  cleavage  appears  to 
depend  in  a  great  measure  upon  their  different  proper 
ties  in  this  respect.     In  butter,  for  example,  the  ne\\ 
attachments  are  equal,  or  nearly  so,  to  the  old,  and  the 
cleavage  is  consequently  indistinct ;  in  wax  this  does  no 
appear  to  be  the  case,  and  hence  may  arise  in  a  grea 
degree  the  perfection  of  its  cleavage.     The  further  ex 
animation  of  this  subject  promises  interesting  results.' 
I  would  dwell  upon  this  point  the  more  distinctly  as  the 
advocates  of  differential  motion  may  deem  it  to  be  in 
their  favour ;  but  it  appears  to  me  that  the  mechanica 
conceptions  applied  in  the  above  passage  are  totally  dif- 
ferent from  theirs.    If  they  think  otherwise,  then  it  seems 
to  me  that  they  should  change  the  expressions  which 


NO   SLIDING  OF  FILAMENTS.  407 

refer  the  differential  motion  to  a  "  drag "  towards  the 
centre,  and  the  structure  to  the  sliding  of  "  filaments  " 
past  each  other  in  consequence  of  this  drag.  Such  fila- 
mentary sliding  may  take  place  in  a  truly  viscous  body, 
but  it  does  not  take  place  in  ice. 

In  one  particular  the  ice  resembles  the  butter  referred 
to  in  the  above  quotation  ;  for  its  new  attachments  appear 
to  be  equal  to  the  old,  and  this,  I  think,  is  to  be  ascribed  to 
its  perfect  regelation.  As  justly  pointed  out  by  Mr.  John 
Ball,  the  veined  ice  of  a  glacier,  if  un weathered,  shows  no 
tendency  to  cleave ;  for  though  the  expulsion  of  the  air- 
bubbles  has  taken  place,  the  reattachment  of  the  particles 
is  so  firm  as  to  abolish  all  evidence  of  cleavage.  When 
the  ice,  on  the  contrary,  is  weathered,  the  plates  become 
detached,  and  I  have  often  been  able  to  split  such  ice  into 
thin  tablets  having  an  area  of  two  or  three  square  feet. 

In  his  Thirteenth  Letter  Professor  Forbes  throws  out  a 
new  and  possibly  a  pregnant  thought  in  connexion  with 
the  veins.  If  I  understand  him  aright —  and  I  confess  it 
is  usually  a  matter  of  extreme  difficulty  with  me  to  make 
sure  of  this  —  he  there  refers  the  veins,  not  to  the  expul- 
sion of  the  air  from  the  ice,  but  to  its  redistribution.  The 
pressure  produces  "  lines  of  tearing  in  which  the  air  is  dis- 
tributed in  the  form  of  regular  globules."  I  do  not  know 
what  might  be  made  of  this  idea  if  it  were  developed,  but 
at  present  I  do  not  see  how  the  supposed  action  could 
produce  the  blue  bands ;  and  I  agree  with  Professor  Wm. 
Thomson  in  regarding  the  explanation  as  improbable.* 

*  For  an  extremely  ingenious  view  of  the  origin  of  the  veined  structure,  I 
would  refer  to  a  paper  by  Professor  Thomson,  in  the  "  Proceedings  of  the 
Royal  Society,"  April,  1858. 


408    INFLUENCE  OF  PRESSURE  ON  BOILING  POINT. 


THE  VEINED  STRUCTURE  AND  THE  LIQUEFAC- 
TION OF  ICE  BY  PRESSURE. 

(31.) 

I  HAVE  already  noticed  an  important  fact  for  which  we 
are  indebted  to  Mr.  James  Thomson,  and  have  referred  to 
the  original  communications  on  the  subject.  I  shall  here 
place  the  physical  circumstances  connected  with  this  fact 
before  my  reader  in  the  manner  which  I  deem  most  likely 
to  interest  him. 

When  a  liquid  is  heated,  the  attraction  of  the  molecules 
operates  against  the  action  of  the  heat,  which  tends  to 
tear  them  asunder.  At  a  certain  point  the  force  of  heat 
triumphs,  the  cohesion  is  overcome,  and  the  liquid  boils. 
But  supposing  we  assist  the  attraction  of  the  molecules 
by  applying  an  external  pressure,  the  difficulty  of  tearing 
them  asunder  will  be  increased ;  more  heat  will  be  re- 
quired for  this  purpose  ;  and  hence  we  say  that  the  boiling 
point  of  the  liquid  has  been  elevated  by  the  pressure. 

If  molten  sulphur  be  poured  into  a  bullet-mould,  it  will 
be  found  on  cooling  to  contract,  so  as  to  leave  a  large 
hollow  space  in  the  middle  of  each  sphere.  Cast  musket- 
bullets  are  thus  always  found  to  possess  a  small  cavity 
within  them  produced  by  the  contraction  of  the  lead. 
Conceive  the  bullet  placed  within  its  mould  and  the 
latter  heated ;  to  produce  fusion,  it  is  necessary  that  the 
sulphur  or  the  lead  should  swell.  Here,  as  in  the  case  of 
the  heated  water,  the  tendency  to  expand  is  opposed  by  the 
attraction  of  the  molecules ;  with  a  certain  amount  of  heat 
however  this  attraction  is  overcome  and  the  solid  melts. 
But  suppose  we  assist  the  molecular  attraction  by  a  suita- 
ble force  applied  externally,  a  greater  amount  of  heat  than 
before  will  be  necessary  to  tear  them  asunder ;  and  hence 


INFLUENCE   OF  PRESSURE   ON  FUSING  POINT.       409 

we  say  that  the  fusing  point  has  been  elevated  by  the  pres- 
sure.    This  fact  has  been  experimentally  established  by- 
Messrs.  Hopkins  and  Fairbairn,  who  applied  to  spermaceti 
and  other  substances  pressures  so  great  as  to  raise  their 
points  of  fusion  a  considerable  number  of  degrees. 

Let  us  now  consider  the  case  of  the  metal  bismuth.  If 
the  molten  metal  be  poured  into  a  bullet-mould  it  will 
expand  on  solidifying.  I  have  myself  filled  a  strong  cast- 
iron  bottle  with  the  metal,  and  found  its  expansion  on 
cooling  sufficiently  great  to  split  the  bottle  from  neck  to 
bottom.  Hence,  in  order  to  fuse  the  bismuth  the  substance 
must  contract,"  and  it  is  manifest  that  an  external  pressure 
which  tends  to  squeeze  the  molecules  more  closely  together 
here  assists  the  heat  instead  of  opposing  it.  Hence,  to 
fuse  bismuth  under  great  pressure,  a  less  amount  of 
heat  will  be  required  than  when  the  pressure  is  removed  ; 
or  in  other  words,  the  fusing  point  of  bismuth  is  lowered 
by  the  pressure.  Now,  in  passing  from  the  solid  to  the 
liquid  state,  ice,  like  bismuth,  contracts,  and,  if  the  con- 
traction be  promoted  by  external  pressure,  as  shown  by 
the  Messrs.  Thomson,  a  less  amount  of  heat  suffices  to 
liquefy  it. 

These  remarks  will  enable  us  to  understand  a  singular 
effect  first  obtained  by  myself  at  the  close  of  1856  or  in 
January  1857,  noticed  at  the  time  in  the  "  Proceedings  " 
of  the  Royal  Society,  and  afterwards  fully  described  in  a 
paper  presented  to  the  Society  in  December  of  that  year. 
A  cylinder  of  clear  ice  two  inches  high  and  an  inch  in 
diameter  was  placed  between  two  slabs  of  box-wood,  and 
subjected  to  a  gradual  pressure.  I  watched  the  ice  in  a 
direction  perpendicular  to  its  length,  and  saw  cloudy  lines 
drawing  themselves  across  it.  As  the  pressure  continued, 
these  lines  augmented  in  numbers,  until  finally  the  prism 
presented  the  appearance  of  a  crystal  of  gypsum  whose 
planes  of  cleavage  had  been  forced  out  of  optical  contact. 
27 


410 


EXPERIMENTS. 


When  looked  at  obliquely  it  was  found  that  the  lines  were 
merely  the  sections  of  flat  dim  surfaces,  which  lay  like 

laminae  one  over  the  other 
throughout  the  length  of 
the  prism.  Fig.  50  repre- 
sents the  prism  as  it  ap- 
peared when  looked  at  in  a 
direction  perpendicular  to 
its  axis ;  Fig.  51  shows  the 
appearance  when  viewed 
Fig.  so.  Fig..5i.  obliquely.* 

At  first  sight  it  might  appear  as  if  air  had  intruded  itself 
between  the  separated  surfaces  of  the  ice,  and  to  test  this 
point  I  placed  a  cylinder  two  inches  long  and  an  inch  wide 
upright  in  a  copper  vessel  which  was  filled  with  ice-cold 
water.  The  ice  cylinder  rose  about  half  an  inch  above  the 
surface  of  the  water.  Placing  the  copper  vessel  on  a  slab 
of  wood,  and  a  second  slab  on  the  top  of  the  cylinder  of 
ice,  the  latter  was  subjected  to  the  gradual  action  of  a 
small  hydraulic  press.  When  the  hazy  surfaces  were  well 
developed  in  the  portion  of  the  ice  above  the  water,  the 
cylinder  was  removed  and  examined:  the  planes  of  rupture 
extended  throughout  the  entire  length  of  the  cylinder, 
just  as  if  it  had  been  squeezed  in  air.  I  subsequently 
placed  the  ice  in  a  stout  vessel  of  glass,  and  squeezed  it, 
as  in  the  last  experiment :  the  surfaces  of  discontinuity 
were  seen  forming  under  the  liquid  quite  as  distinctly  as 
in  air. 

To  prove  that  the  surfaces  were  due  to  compression  and 
not  to  any  tearing  asunder  of  the  mass  by  tension,  the  fol- 
lowing experiment  was  made :  — A  cylindrical  piece  of  ice, 
one  of  whose  ends,  however,  was  not  parallel  to  the  other, 
was  placed  between  the  slabs  of  wood,  and  subjected  to 

*  This  effect  projected  upon  a  screen  is  a  most  striking  and  instructive 
class  experiment. 


LIQUID  LAYERS  PRODUCED  BY  PRESSURE.        411 

pressure.   Fig.  52  shows  the  disposition  of  the  experiment. 
The  effect  upon  the  ice-cylinder  was  that  shown  in  Fig.  53, 


Fig.  52. 


Fig.  53. 


the  surfaces  being  developed  along  that  side  which  had 
suffered  the  pressure.  On  examining  the  surfaces  by  a 
pocket  lens  they  resembled  the  effect  produced  upon  a 
smooth  cold  surface  by  breathing  on  it. 

The  surfaces  were  always  dim ;  and  had  the  spaces  been 
filled  with  air,  or  were  they  simply  vacuous,  the  reflection 
of  light  from  them  would  have  been  so  copious  as  to  ren- 
der them  much  more  brilliant  than  they  were  observed  to 
be.  To  examine  them  more  particularly  I  placed  a  con- 
cave mirror  so  as  to  throw  the  diffused  daylight  from  a 
window  full  upon  the  cylinder.  On  applying  the  pressure 
dim  spots  were  sometimes  seen  forming  in  the  very  middle 
of  the  ice,  and  these  as  they  expanded  laterally  appeared 
to  be  in  a  state  of  intense  motion,  which  followed  closely 
the  edge  of  each  surface  as  it  advanced  through  the  solid 
ice.  Once  or  twice  I  observed  the  hazy  surfaces  pioneered 
through  the  mass  by  dim  offshoots,  apparently  liquid,  and 
constituting  a  kind  of  decrystallization.  From  the  closest 
examination  to  which  I  was  able  to  subject  them,  the 
surfaces  appeared  to  me  to  be  due  to  internal  liquefac- 
tion ;  indeed,  when  the  melting  point  of  ice,  having 
already  a  temperature  of  32°,  is  lowered  by  pressure,  its 
excess  of  heat  must  instantly  be  applied  to  produce  this 
effect. 

I  have  already  given  a  drawing  (p.  386)  showing  the 


412     APPLICATION  TO  THE  VEINED   STRUCTURE. 

development  of  the  veined  structure  at  the  base  of  the  ice- 
cascade  of  the  Rhone ;  and  if  we  compare  that  diagram  with 
Fig.  53  a  striking  similarity  at  once  reveals  itself.  The 
ice  of  the  glacier  must  undoubtedly  be  liquefied  to  some 
extent  by  the  tremendous  pressure  to  which  it  is  here  sub- 
jected. Surfaces  of  discontinuity  will  in  all  probability 
be  formed,  which  facilitate  the  escape  of  the  imprisoned 
air.  The  small  quantity  of  water  produced  will  be  partly 
imbibed  by  the  adjacent  porous  ice,  and  will  be  refrozen 
when  relieved  from  the  pressure.  This  action,  associated 
with  that  ascribed  to  pressure  in  the  last  section,  appears 
to  me  to  furnish  a  complete  physical  explanation  of  the 
laminated  structure  of  glacier-ice. 


GENERAL  APPEARANCE   OF   WHITE  ICE-SEAMS.      413 


WHITE  ICE-SEAMS  IN  THE  GLACIER  DU  GEANT. 

(32.) 

ON  the  28th  of  July,  1857,  while  engaged  upon  the 
Glacier  du  Ge*ant,  my  attention  was  often  attracted  by 
protuberant  ridges  of  what  at  first  appeared  to  be  pure 
white  snow,  but  which  on  examination  I  found  to  be 
compact  ice  filled  with  innumerable  round  air-cells  ;  and 
which,  in  virtue  of  its  greater  power  of  resistance  to 
wasting,  -often  rose  to  a  height  of  three  or  four  feet  above 
the  general  level  of  the  ice.  As  I  stood  amongst  these 
ridges,  they  appeared  detached  and  without  order  of  ar- 
rangement, but  looked  at  from  a  distance  they  were  seen 
to  sweep  across  the  proper  Glacier  du  Geant  in  a  direction 
concentric  with  its  dirt-bands  and  its  veined  structure. 
In  some  cases  the  seams  were  admirable  indications  of 
the  relative  displacement  of  two  adjacent  portions  of  the 
glacier,  which  were  divided  from  each  other  by  a  crevasse. 
Usually  the  sections  of  a  seam  exposed  on  the  opposite 
sides  of  a  fissure  accurately  faced  each  other,  and  the 
direction  of  the  seam  on  both  sides  was  continuous  ;  but 
at  other  places  they  demonstrated  the  existence  of  lateral 
faults,  being  shifted  asunder  laterally  through  spaces 
varying  from  a  few  inches  to  six  or  seven  feet. 

On  the  following  day  I  was  again  upon  the  same  gla- 
cier, and  noticed  in  many  cases  the  white  ice-seams  ex- 
quisitely honeycombed.  The  case  was  illustrative  of  the 
great  difference  between  the  absorptive  power  of  the  ice 
itself  and  of  the  objects  which  lie  upon  its  surface.  Deep 
cylindrical  cells  were  produced  by  spots  of  black  dirt 
which  had  been  scattered  upon  the  surface  of  the  white 
ice,  and  which  sank  to  a  depth  of  several  inches  into  the 


414 


SECTIONS  OF  SEAMS. 


mass.  I  examined  several  sections  of  the  veins,  and  in 
general  I  found  that  their  deeper  portions  blended  gradu- 
ally with  the  ice  on  either  side  of  them.  But  higher  up 
the  glacier  I  found  that  the  veins  penetrated  only  to  a 
limited  depth,  and  did  not  therefore  form  an  integrant 


A  A 


Fig.  54.  Fig.  55. 

portion  of  the  glacier.  Figs.  54  and  55  show  the  sections 
of  two  of  the  seams  which  were  exposed  on  the  wall  of  a 
crevasse  at  some  distance  below  the  great  ice-fall  of  the 
Glacier  du  Ge*ant. 

It  was  at  the  base  of  the  TalSfre  cascade  that  the  expla- 
nation of  these  curious  seams  presented  itself  to  me.  In 
one  of  my  earliest  visits  to  this  portion  of  the  glacier  I 

was  struck  by  a  singular  dispo- 
sition of  the  blue  veins  on  the 
vertical  wall  of  a  crevasse.  Fig. 
56  will  illustrate  what  I  saw. 
vemgj  within  a  short  dis- 


Fig. 56. 


tance,  dipped  backward  and  for  ward,  like  the  junctions  of 


VARIATIONS  IN  "DIP"  OF  STRUCTURE.          415 

stones  used  to  turn  an  arch.     In  some  cases  I  found  this 
variation  of  the  structure  so  great  as  to  pass  in  a  short 
distance  from  the  vertical  to 
the  horizontal,   as   shown   in 
Pig.  57. 

Further  examination  taught 
me  that  the  glacier  here  is 
crumpled  in  a  most  singular 
manner  ;  doubtless  by  the 
great  pressure  to  which  it  /v'n  Fig  57 

is  exposed.  The  following 
illustration  will  convey  a  notion  of  its  aspect.  Let  one 
hand  be  laid  flat  upon  a  table,  palm  downwards,  and  let 
the  fingers  be  bent  until  the  space  between  the  first  joint 
and  the  ends  of  the  fingers  is  vertical ;  one  of  the  crum- 
ples to  which  I  refer  will  then  be  represented.  The  ice 
seems  bent  like  the  fingers,  and  the  crumples  of  the  gla- 
cier are  cut  by  crevasses,  which  are  accurately  typified  by 
the  spaces  between  the  fingers.  Let  the  second  hand  now 
be  placed  upon  the  first,  as  the  latter  is  upon  the  table,  so 
that  the  tops  of  the  bent  fingers  of  the  second  hand  shall 
rest  upon  the  roots  of  the  first :  two  crumples  would  thus 
be  formed  ;  a  series  of  such  protuberances,  with  steep 
fronts,  follow  each  other  from  the  base  of  the  TalSfre 
cascade  for  some  distance  downwards. 

On  Saturday  the  1st  of  August  I  ascended  these  rounded 
terraces  in  succession,  and  observed  among  them  an  ex- 
tremely remarkable  disposition  of  the  structure.  Fig.  58 
is  a  section  of  a  series  of  three  of  the  crumples,  on  which 
the  shading  lines  represent  the  direction  of  the  blue  veins. 
At  the  base  of  each  protuberance  I  found  a  seam  of  white 
ice  wedged  firmly  into  the  glacier,  and  each  of  the  seams 
marked  a  place  of  dislocation  of  the  veins.  The  white 
seams  thinned  off  gradually,  and  finally  vanished  where 
the  violent  crumpling  of  the  ice  disappeared.  In  Fig.  59 


416 


CRUMPLES   OF  THE   TALEFRE. 


I  have  sketched  the  wall  of  a  crevasse,  which  represents 
what  may  be  regarded  as  the  incipient  crumpling.     The 


Fig.  58. 


undulating  line  shows  the  contour  of  the  surface,  and  the 
shading  lines  of  the  veins.  It  will  be  observed  that  the 
direction  of  the  veins  yields  in  conformity  with  the  undu- 
lation of  the  surface ;  and  an  augmentation  of  the  effect 
would  evidently  result  in  the  crumples  shown  in  Fig.  58. 
The  appearance  of  the  white  seams  at  those  places  where 
a  dislocation  occurred  was,  as  far  as  I  could  observe,  in- 
variable ;  but  in  a  few  instances  the  seams  were  observed 
upon  the  platforms  of  the  terraces,  and  also  upon  their 
slopes.  The  width  of  a  seam  was  very  irregular,  varying 
from  a  few  inches  at  some  places  to  three  or  four  feet  at 
others. 

On  the  3rd  of  August  I  was  again  at  the  base  of  the 
TalSfre  cascade,  and  observed  a  fact,  the  significance  of 


MOULDS   OF  WHITE  ICE-SEAMS.  417 

which  had  previously  escaped  me.  The  rills  which  ran 
down  the  ice-slopes  collected  at  the  base  of  each  protu- 
berance into  a  stream,  which,  at  the  time  of  my  visit,  had 
hollowed  out  for  itself  a  deep  channel  in  the  ice.  At  some 
places  the  stream  widened,  at  others  its  banks  of  ice  ap- 
proached each  other,  and  rapids  were  produced ;  in  fact, 
the  channel  of  such  streams  appeared  to  be  the  exact 
moulds  of  the  seams  of  white  ice. 

Instructed  thus  far,  I  ascended  the  Glacier  du  Ge*ant  on 
the  5th  of  August,  and  then  observed  on  the  wrinkles  of 
this  glacier  the  same  leaning  backwards  and  forwards  of 
the  blue  veins  as  I  had  previously  observed  upon  the 
Tal£fre.  I  also  noticed  on  this  day  that  a  seam  of  white 
ice  would  sometimes  open  out  into  two  branches,  which, 
after  remaining  for  some  distance  separate,  would  reunite 
and  thus  enclose  a  little  glacier-island.  At  other  places 
lateral  branches  were  thrown  off  from  the  principal  seam, 
thus  suggesting  the  form  of  a  glacier-rivulet  which  had 
been  fed  by  tributary  branches.  On  the  7th  of  August 
I  hunted  the  seams  still  farther  up  the  glacier ;  and  found 
them  at  one  place  descending  a  steep  ice-hill,  being  crossed 
by  other  similar  bands,  which  however  were  far  less  white 
and  compact.  I  followed  these  new  bands  to  their  origin, 
and  found  it  to  be  a  system  of  crevasses  formed  at  the 
summit  of  the  hill,  some  of  which  were  filled  with  snow. 
Lower  down  the  crevasses  closed,  and  the  snow  thus 
jammed  between  their  walls  was  converted  into  white  ice. 
These  seams,  however,  never  attained  the  compactness  and 
prominence  of  the  larger  ones  which  had  their  origin  far 
higher  up.  I  singled  out  one  of  the  best  of  the  latter,  and 
traced  it  through  all  the  dislocation  and  confusion  of  the 
ice,  until  I  found  it  to  terminate  in  a  cavity  filled  with  snow. 

This  was  near  the  base  of  the  seracs,  and  the  streams 
here  were  abundant.  Comparing  the  shapes  of  some  of 
them  with  that  of  the  ice-bands  lower  down  the  glacier,  a 


418 


STREAMS   AND   SEAMS. 


striking  resemblance  was  observed.    Fig.  60  is  the  plan  of 
a  deep-cut  channel  through  which  a  stream  flowed  on  the 


Fig.  60. 


day  to  which  I  now  refer.    Fig.  61  is  the  plan  of  a  seam  of 
white  ice  sketched  on  the  same  day,  low  down  upon  the 


Fig.  61. 

glacier.  Instances  of  this  kind  might  be  multiplied ;  and 
the  result,  I  think,  renders  it  certain  that  the  white  ice- 
seams  referred  to  are  due  to  the  filling  up  of  the  channels 
of  glacier-streams  by  snow  during  the  winter,  and  the  sub- 
sequent compression  of  the  mass  to  ice  during  the  descent 
of  the  glacier.  I  have  found  such  seams  at  the  bases  of  all 
cascades  that  I  have  visited  ;  and  in  all  cases  they  appear 
to  be  due  to  the  same  cause.  The  depth  to  which  they 
penetrate  the  glacier  must  be  profound,  or  the  ablation  of 
the  ice  must  be  less  than  what  is  generally  supposed ;  for 
the  seams  formed  so  high  up  on  the  Glacier  du  G£ant  may 
be  traced  low  down  upon  the  trunk-stream  of  the  Mer  de 
Glace.* 

These  observations  on  the  white  ice-seams  enable  us  to 
add  an  important  supplement  to  what  has  been  stated 
regarding  the  origin  of  the  dirt-bands  of  the  Mer  de 

*  The  more  permanent  seams  may  possibly  be  due  to  the  filling  of  the 
profound  crevasses  of  the  cascade. 


SCALING  OFF  BY  PRESSURE.  419 

Glace.  The  protuberances  at  the  base  of  the  cascade  are 
due  not  only  to  the  toning  down  of  the  ridges  produced 
by  the  transverse  fracture  of  the  glacier  at  the  summit  of 
the  fall,  but  they  undergo  modifications  by  the  pressure 
locally  exerted  at  its  base.  The  state  of  things  represented 
in  Fig.  57  is  plainly  due  to  the  partial  pushing  of  one  crum- 
ple over  that  next  in  advance  of  it.  There  seems  to  be  a 
differential  motion  of  the  parts  of  the  glacier  in  the  same 
longitudinal  line ;  showing  that  upon  the  general  motion 
of  the  glacier  smaller  local  motions  are  superposed.  The 
occurrence  of  the  seams  upon  the  faces  of  the  slopes  seems 
also  to  prove  that  the  pressure  is  competent,  in  some  cases, 
to  cause  the  bases  of  the  protuberances  to  swell,  so  that 
what  was  once  the  base  of  a  crumple  may  subsequently 
form  a  portion  of  its  slope.  Another  interesting  fact  is 
also  observed  where  the  pressure  is  violent :  the  crumples 
scale  off,  bows  of  ice  being  thus  formed  which  usually 
span  the  crumples  over  their  most  violently  compressed 
portions.  I  have  found  this  scaling  off  at  the  bases  of  all 
the  cascades  which  I  have  visited,  and  it  is  plainly  due  to 
the  pressure  exerted  at  such  places  upon  the  ice. 


(33.) 

NOT  only  at  the  base  of  its  great  cascade,  but  through- 
out the  greater  part  of  its  length,  the  Glacier  du  Ge*ant  is 
in  a  state  of  longitudinal  compression.  The  meaning  of 
this  term  will  be  readily  understood :  Let  two  points,  for 
example,  be  marked  upon  the  axis  of  the  glacier ;  if  these 
during  its  descent  were  drawn  wider  apart,  it  would  show 
that  the  glacier  was  in  a  state  of  longitudinal  strain  or 
tension  ;  if  they  remained  at  the  same  distance  apart, 
it  would  indicate  that  neither  strain  nor  pressure  was 
exerted  ;  whereas,  if  the  two  points  approached  each 


420          COMPRESSION  OF  GLACIER  DU  GEANT. 

other,  which  could  only  be  by  the  quicker  motion  of  the 
hinder  one,  the  existence  of  longitudinal  compression 
would  be  thereby  demonstrated. 

Taking  "  Le  Petit  Balmat"  with  me,  to  carry  my  theo- 
dolite, I  ascended  the  Glacier  du  Ge*ant  until  I  came  near 
the  place  where  it  is  joined  by  the  Glacier  des  Pe*riades, 
and  whence  I  observed  a  patch  of  fresh  green  grass  upon 
the  otherwise  rocky  mountain-side.  To  this  point  I 
climbed,  and  made  it  the  station  for  my  instrument. 
Choosing  a  well-defined  object  at  the  opposite  side  of  the 
glacier,  I  set,  on  the  9th  of  August,  in  the  line  between 
this  object  and  the  theodolite,  three  stakes,  one  in  the 
centre  of  the  glacier,  and  the  other  two  at  opposite  sides 
of  the  centre,  and  about  100  yards  from  it.  This  done,  I 
descended  for  a  quarter  of  a  mile,  when  I  again  climbed 
the  flanking  rocks,  placing  my  theodolite  in  a  couloir, 
down  which  stones  are  frequently  discharged  from  the 
end  of  a  secondary  glacier  which  hangs  upon  the  heights 
above.  Here,  as  before,  I  fixed  three  stakes,  chiselled 
a  mark  upon  the  granite,  so  as  to  enable  me  to  find 
the  place,  and  regained  the  ice  without  accident.  A  day 
or  two  previously  we  had  set  out  a  third  line  at  some 
distance  lower  down,  and  I  was  thus  furnished  with  a 
succession  of  points  along  the  glacier,  the  relative  motions 
of  which  would  decide  whether  it  was  pressed  or  stretched 
in  the  direction  of  its  length.  On  the  10th  of  August 
Mr.  Huxley  joined  us ;  and  on  the  following  day  we  all 
set  out  for  the  Glacier  du  Geant,  to  measure  the  progress 
of  the  stakes  which  I  had  fixed  there.  Hirst  remained 
upon  the  glacier  to  measure  the  displacements ;  I  shoul- 
dered the  theodolite ;  and  Huxley  was  my  guide  to  the 
mountain-side,  sounding  in  advance  of  me  the  treacherous- 
looking  snow  over  which  we  had  to  pass. 

Calling  the  central  stake  of  the  highest  line  No.  1,  that 
of  the  middle  line  No.  2,  arid  that  of  the  line  nearest  the 


STRUCTURE  IN  WHITE  ICE-SEAMS.  421 

Tacul  No.  3,  the  following  are  the  spaces  moved  over  by 
hese  three  points  in  twenty-four  hours :  — 

Inches.  Distances  asunder. 

No.  1 20.55  j  545  yards. 

No.  2.         .         .         .         15.43] 

No.  3.    ,  12.75  487  yards. 


422  PARTIAL   SUMMARY. 


PARTIAL   SUMMARY. 

1.  GLACIERS  are  derived  from  mountain  snow,  whicli 
has  been  consolidated  to  ice  by  pressure. 

2.  That  pressure  is  competent  to  convert  snow  into  ice 
has  been  proved  by  experiment. 

3.  The  power  of  yielding  to  pressure  diminishes  as  the 
mass  becomes  more  compact ;  but  it  does  not  cease  ever 
when  the  substance  has  attained  the  compactness  whicl 
would  entitle  it  to  be  called  ice. 

4.  When  a  sufficient  depth  of  such  a  substance  collects 
upon  the  earth's  surface,  the  lower  portions  are  squeezec 
out  by  the  pressure  of  the  superincumbent  mass.     If  ii 
rests  upon  a  slope  it  will  yield  principally  in  the  directior 
of  the  slope,  and  move  downwards. 

5.  In  addition  to  this,  the  whole  mass  slides  bodily  aloii£ 
its  inclined  bed,  and  leaves  the  traces  of  its  sliding  on  the 
rocks  over  which  it  passes,  grinding  off  their  asperities  anc 
marking  them  with  grooves  and  scratches  in  the  directior 
of  the  motion. 

6.  In  this  way  the  deposit  of  consolidated  and  uncon 
solidated  snow  which  covers  the  higher  portions  of  loftj 
mountains  moves  slowly  down  into  an  adjacent  valley 
through  which  it  descends  as  a  true  glacier,  partly  bj 
sliding  and  partly  by  the  yielding  of  the  mass  itself. 

7.  Several  valleys  thus  filled  may  unite  in  a  single  val 
ley,  the  tributary  glaciers  welding  themselves  together  tc 
form  a  trunk-glacier. 

8.  Both  the  main  valley  and  its  tributaries  are  ofter 
sinuous,  and  the  tributaries  must  change  their  direction  t( 
form  the  trunk ;  the  width  of  the  valley  often  varies.   Th< 
glacier  is  forced  through  narrow  gorges,  widening  after  i 
lias  passed  them ;  the  centre  of  the  glacier  moves  mo 


PARTIAL   SUMMARY.  423 

quickly  than  the  sides,  and  the  surface  more  quickly  than 
the  bottom  ;  the  point  of  swiftest  motion  follows  the  same 
law  as  that  observed  in  the  flow  of  rivers,  shifting  from 
one  side  of  the  centre  to  the  other  as  the  flexure  of  the 
valley  changes. 

9.  These  various  effects  may  be  reproduced  by  experi- 
ments on  small  masses  of  ice.     The  substance  may  more- 
over be  moulded  into  vases  and  statuettes.     Straight  bars 
of  it  may  be  bent  into  rings,  or  even  coiled  into  knots. 

10.  Ice  capable  of  being  thus  moulded  is  practically 
incapable  of  being  stretched.     The  condition  essential  to 
success  is  that  the  particles  of  the  ice  operated  on  shall 
be  kept  in  close  contact,  so  that  when  old  attachments 
have  been  severed  new  ones  may  be  established. 

11.  The  nearer  the  ice  is  to  its  melting  point  in  tem- 
perature, the  more  easily  are  the  above  results  obtained ; 
when  ice  is  many  degrees  below  its  freezing  point  it  is 
crushed  by  pressure  to  a  white  powder,  and  is  not  capable 
of  being  moulded  as  above. 

12.  Two  pieces  of  ice  at  32°  Fahr.,  with  moist  surfaces, 
when  placed  in  contact  freeze  together  to  a  rigid  mass ; 
this  is  called  Reg-elation. 

13.  When  the  attachments  of  pressed  ice  are  broken, 
the  continuity  of  the  mass  is  restored  by  the  regelation 
of  the  new  contiguous  surfaces.     Regelation  also  enables 
two  tributary  glaciers  to  weld  themselves  to  form  a  con- 
tinuous trunk  ;  thus  also  the  crevasses  are  mended,  and 
the  dislocations  of  the  glacier  consequent  on  descending 
cascades  are  repaired.     This  healing  of  ruptures  extends 
to  the  smallest  particles  of  the  mass,  and  it  enables  us  to 
account  for  the  continued  compactness  of  the  ice  during 
the  descent  of  the  glacier. 

14.  The  quality   of  viscosity  is  practically  absent  in 
glacier-ice.     Where  pressure   comes  into  play  the  phe- 
nomena are  suggestive  of  viscosity,  but  where  tension 


424  PARTIAL   SUMMARY. 

comes  into  play  the  analogy  with  a  viscous  body  breaks 
down.  When  subjected  to  strain  the  glacier  does  not 
yield  by  stretching,  but  by  breaking  ;  this  is  the  origin  of 
the  crevasses. 

15.  The  crevasses  are  produced  by  the  mechanical  strains 
to  which  the  glacier  is  subjected.     They  are  divided  into 
marginal,  transverse,  and  longitudinal  crevasses ;  the  first 
produced  by  the  oblique  strain  consequent  on  the  quicker 
motion  of  the  centre  ;  the  second  by  the  passage  of  the 
glacier  over  the  summit  of  an  incline  ;  the  third  by  pres- 
sure from  behind  and  resistance  in  front,  which  causes 
the  mass  to  split  at  right  angles  to  the  pressure. 

16.  The  moulins  are  formed  by  deep  cracks  intersect- 
ing glacier  rivulets.   The  water  in  descending  such  cracks 
scoops  out  for  itself  a  shaft,  sometimes  many  feet  wide, 
and  some  hundreds  of  feet  deep,  into  which  the  cataract 
plunges  with  a  sound  like  thunder.     The  supply  of  water 
is  periodically  cut  off  from  the  moulins  by  fresh  cracks, 
in  which  new  moulins  are  formed. 

17.  The  lateral  moraines  are  formed  from  the  ddbris 
which  loads  the  glacier  along  its  edges  ;  the  medial  mo- 
raines are  formed  on  a  trunk-glacier  by  the  union  of  the 
lateral  moraines  of  its  tributaries  ;  the  terminal  moraines 
are  formed  from  the  debris  carried  by  the  glacier  to  its 
terminus,  and  there  deposited.     The  number  of  medial 
moraines  on  a  trunk-glacier  is  always  one  less  than  the 
number  of  tributaries. 

18.  When  ordinary  lake-ice  is  intersected  by  a  strong 
sunbeam  it  liquefies  so  as  to  form  flower-shaped  figures 
within  the  mass  ;  each  flower  consists  of  six  petals  with 
a  vacuous  space  at  the  centre  :   the   flowers  are  always 
formed  parallel  to  the  planes  of  freezing,  and  depend  on 
the  crystallization  of  the  substance. 

19.  Innumerable  liquid  disks,  with  vacuous  spots,  are 
also  formed  by  the  solar  beams  in  glacier-ice.   These  empty 


PARTIAL  SUMMARY.  425 

spaces  have  been  hitherto  mistaken  for  air-bubbles,  the  flat 
form  of  the  disks  being  erroneously  regarded  as  the  result 
of  pressure. 

20.  These  disks  are  indicators  of  the  intimate  constitu- 
tion of  glacier-ice,  and  they  teach  us  that  it  is  composed 
of  an  aggregate  of  parts  with  surfaces  of  crystallization  in 
all  possible  planes. 

21.  There  are  also  innumerable  small  cells  in  glacier- 
ice  holding  air  and  water ;  such  cells  also  occur  in  lake- 
ice  ;  and  here  they  are  due  to  the  melting  of  the  ice  in 
contact  with  the  bubble  of  air.     Experiments  are  needed 
on  glacier-ice  in  reference  to  this  point. 

22.  At  a  free  surface  within  or  without,  ice  melts  with 
more  ease  than  in  the  centre  of  a  compact  mass.     The 
motion  which  we  call  heat  is  less  controlled  at  a  free  sur- 
face, and  it  liberates  the  molecules  from  the  solid  condition 
sooner  than  when  the  atoms  are  surrounded  on  all  sides 
by   other  atoms  which  impede  the   molecular  motion. 
Regelation  is  the  complementary  effect  to  the  above ;  for 
here  the  superficial  portions  of  a  mass  of  ice  are  made 
virtually  central  by  the  contact  of  a  second  mass. 

23.  The  dirt-bands  have  their  origin  in  the  ice-cascades. 
The  glacier,  in  passing  the  brow,  is  transversely  fractured ; 
ridges  are  formed  with  hollows  between  them ;  these  trans- 
verse hollows  are  the  principal  receptacles  of  the  fine 
debris  scattered  over  the  glacier ;  and  after  the  ridges 
have  been  melted  away,  the  dirt  remains  in  successive 
stripes  upon  the  glacier. 

24.  The  ice  of  many  glaciers  is  laminated,  and  when 
weathered  may  be  cloven  into  thin  plates.     In  the  sound 
ice  the  lamination  manifests  itself  in  blue  stripes  drawn 
through  the  general  whitish  mass  of  these  glaciers  ;  these 
blue  veins  representing  portions  of  ice  from  which  the  air- 
bubbles  have  been  more  completely  expelled.    This  is  the 
veined  structure  of  the  ice.     It  is  divided  into  marginal, 

.     28 


426  PARTIAL  SUMMARY. 

transverse,  and  longitudinal  structure ;  which  may  be 
regarded  as  complementary  to  marginal,  longitudinal,  and 
transverse  crevasses.  The  latter  are  produced  by  tension, 
the  former  by  pressure,  which  acts  in  two  different  ways  : 
firstly,  the  pressure  acts  upon  the  ice  as  it  has  acted  upon 
rocks  which  exhibit  the  lamination  technically  called  cleav- 
age ;  secondly,  it  produces  partial  liquefaction  of  the  ice. 
The  liquid  spaces  thus  formed  help  the  escape  of  the  air 
from  the  glacier  ;  and  the  water  produced,  being  refrozen 
when  the  pressure  is  relieved,  helps  to  form  the  blue 
veins. 


APPENDIX. 


COMPARATIVE  VIEW  OF  THE  CLEAVAGE  OF 
CRYSTALS  AND  SLATE-ROCKS. 

A  LECTURE  DELIVERED  AT  THE  ROYAL  INSTITUTION,  ON 
FRIDAY  EVENING,  THE  6TH  OF  JUNE,  1856.* 


WHEN  the  student  of  physical  science  has  to  investigate  the  charac- 
ter of  any  natural  force,  his  first  care  must  be  to  purify  it  from  the 
mixture  of  other  forces,  and  thus  study  its  simple  action.  If,  for  exam- 
ple, he  wishes  to  know  how  a  mass  of  water  would  shape  itself,  suppos- 
ing it  to  be  at  liberty  to  follow  the  bent  of  its  own  molecular  forces,  he 
must  see  that  these  forces  have  free  and  undisturbed  exercise.  We 
might  perhaps  refer  him  to  the  dew-drop  for  a  solution  of  the  question ; 
but  here  we  have  to  do,  not  only  with  the  action  of  the  molecules  of  the 
liquid  upon  each  other,  but  also  with  the  action  of  gravity  upon  the 
mass,  which  pulls  the  drop  downwards  and  elongates  it.  If  he  would 
examine  the  problem  in  its  purity,  he  must  do  as  Plateau  has  done, 
withdraw  the  liquid  mass  from  the  action  of  gravity,  and  he  would  then 
find  the  shape  of  the  mass  to  be  perfectly  spherical.  Natural  processes 
come  to  us  in  a  mixed  manner,  and  to  the  uninstructed  mind  are  a 
mass  of  unintelligible  confusion.  Suppose  half  a  dozen  of  the  best  mu- 
sical performers  to  be  placed  in  the  same  room,  each  playing  his  own 
instrument  to  perfection  :  though  each  individual  instrument  might  be 
a  well-spring  of  melody,  still  the  mixture  of  all  would  produce  mere 
noise.  Thus  it  is  with  the  processes  of  nature.  In  nature,  mechanical 
and  molecular  laws  mingle,  and  create  apparent  confusion.  Their 
mixture  constitutes  what  may  be  called  the  noise  of  natural  laws,  and 
it  is  the  vocation  of  the  man  of  science  to  resolve  this  noise  into  its  com- 
ponents, and  thus  to  detect  the  "  music "  in  which  the  foundations  of 
nature  are  laid. 

The  necessity  of  this  detachment  of  one  force  from  all  other  forces  is 
nowhere  more  strikingly  exhibited  than  in  the  phenomena  of  crystal- 
lization. I  have  here  a  solution  of  sulphate  of  soda.  Prolonging  the 

*  Referred  to  in  the  Introduction. 


430  APPENDIX. 

mental  vision  beyond  the  boundaries  of  sense,  we  see  the  atoms  of  that 
liquid,  like  squadrons  under  the  eye  of  an  experienced  general,  arrang- 
ing themselves  into  battalions,  gathering  round  a  central  standard,  and 
forming  themselves  into  solid  masses,  which  after  a  time  assume  the 
visible  shape  of  the  crystal  which  I  here  hold  in  my  hand.  I  may,  like 
an  ignorant  meddler  wishing  to  hasten  matters,  introduce  confusion  into 
this  order.  I  do  so  by  plunging  this  glass  rod  into  the  vessel.  The 
consequent  action  is  not  the  pure  expression  of  the  crystalline  forces ; 
the  atoms  rush  together  with  the  confusion  of  an  unorganized  mob,  and 
not  with  the  steady  accuracy  of  a  disciplined  host.  Here,  also,  in  this 
mass  of  bismuth  we  have  an  example  of  this  confused  crystallization ; 
but  in  the  crucible  behind  me  a  slower  process  is  going  on :  here  there 
is  an  architect  at  work  "  who  makes  no  chips,  no  din,"  and  who  is  now 
building  the  particles  into  crystals,  similar  in  shape  and  structure  to 
those  beautiful  masses  which  we  see  upon  the  table.  By  permitting 
alum  to  crystallize  in  this  slow  way,  we  obtain  these  perfect  octahe- 
drons ;  by  allowing  carbonate  of  lime  to  crystallize,  nature  produces 
these  beautiful  rhomboids;  when  silica  crystallizes,  we  have  formed 
these  hexagonal  prisms  capped  at  the  ends  by  pyramids ;  by  allowing 
saltpetre  to  crystallize,  we  have  these  prismatic  masses  ;  and  when  car- 
bon crystallizes,  we  have  the  diamond.  If  we  wish  to  obtain  a  perfect 
crystal,  we  must  allow  the  molecular  forces  free  play  :  if  the  crystalliz- 
ing mass  be  permitted  to  rest  upon  a  surface  it  will  be  flattened,  and 
to  prevent  this  a  small  crystal  must  be  so  suspended  as  to  be  surrounded 
on  all  sides  by  the  liquid,  or,  if  it  rest  upon  the  surface,  it  must  be 
turned  daily  so  as  to  present  all  its  faces  in  succession  to  the  working 
builder.  In  this  way  the  scientific  man  nurses  these  children  of  his 
intellect,  watches  over  them  with  a  care  worthy  of  imitation,  keeps  all 
influences  away  which  might  possibly  invade  the  strict  morality  of  crys- 
talline laws,  and  finally  sees  them  developed  into  forms  of  symmetry 
and  beauty  which  richly  reward  the  care  bestowed  upon  them. 

In  building  up  crystals,  these  little  atomic  bricks  often  arrange  them- 
selves into  layers,  which  are  perfectly  parallel  to  each  other,  and  which 
can  be  separated  by  mechanical  means ;  this  is  called  the  cleavage  of 
the  crystal.  I  have  here  a  crystallized  mass  which  has  thus  far  escaped 
the  abrading  and  disintegrating  forces  which,  sooner  or  later,  determine 
the  fate  of  sugar-candy.  If  I  am  skilful  enough,  I  shall  discover  that 
this  crystal  of  sugar  cleaves  with  peculiar  facility  in  one  direction. 
Here,  again,  I  have  a  mass  of  rock-salt :  I  lay  my  knife  upon  it,  and 
with  a  blow  cleave  it  in  this  direction ;  but  I  find  on  further  examining 
this  substance  that  it  cleaves  in  more  directions  than  one.  Laying  my 
knife  at  right  angles  to  its  former  position,  the  crystal  cleaves  again ; 


APPENDIX.  431 

and,  finally,  placing  the  knife  at  right  angles  to  the  two  former  positions, 
the  mass  cleaves  again.  Thus  rock-salt  cleaves  in  three  directions,  and 
the  resulting  solid  is  this  perfect  cube,  which  may  be  broken  up  into 
any  number  of  smaller  cubes.  Here  is  a  mass  of  Iceland  spar,  which 
also  cleaves  in  three  directions,  not  at  right  angles,  but  obliquely  to 
each  other,  the  resulting  solid  being  a  rhomboid.  In  each  of  these 
cases  the  mass  cleaves  with  equal  facility  in  all  three  directions.  For 
the  sake  of  completeness,  I  may  say  that  many  substances  cleave  with 
unequal  facility  in  different  directions,  and  the  heavy  spar  I  hold  in  my 
hand  presents  an  example  of  this  kind  of  cleavage. 

Turn  we  now  to  the  consideration  of  some  other  phenomena  to  which 
the  term  cleavage  may  be  applied.  This  piece  of  beech-wood  cleaves 
with  facility  parallel  to  the  fibre,  and  if  our  experiments  were  fine 
enough  we  should  discover  that  the  cleavage  is  most  perfect  when  the 
edge  of  the  axe  is  laid  across  the  rings  which  mark  the  growth  of  the 
tree.  The  fibres  of  the  wood  lie  side  by  side,  and  a  comparatively 
small  force  is  sufficient  to  separate  them.  If  you  look  at  this  mass  of 
hay  severed  from  a  rick,  you  will  see  a  sort  of  cleavage  developed  in  it 
also ;  the  stalks  lie  in  parallel  planes,  and  only  a  small  force  is  required 
to  separate  them  laterally.  But  we  cannot  regard  the  cleavage  of  the 
tree  as  the  same  in  character  as  the  cleavage  of  the  hayrick.  In  the 
one  case  it  is  the  atoms  arranging  themselves  according  to  organic  laws 
which  produce  a  cleavable  structure ;  in  the  other  case  the  easy  sepa- 
ration in  a  certain  direction  is  due  to  the  mechanical  arrangement  of 
the  coarse  sensible  masses  of  the  stalks  of  hay. 

In  like  manner  I  find  that  this  piece  of  sandstone  cleaves  parallel  to 
the  planes  of  bedding.  This  rock  was  once  a  powder,  more  or  less 
coarse,  held  in  mechanical  suspension  by  water.  The  powder  was  com- 
posed of  two  distinct  parts,  fine  grains  of  sand  and  small  plates  of  mica. 
Imagine  a  wide  strand  covered  by  a  tide  which  holds  such  powder  in 
suspension :  *  how  will  it  sink  ?  The  rounded  grains  of  sand  will  reach 
the  bottom  first,  the  mica  afterwards,  and  when  the  tide  recedes  we 
have  the  little  plates  shining  like  spangles  upon  the  surface  of  the  sand. 
Each  successive  tide  brings  its  charge  of  mixed  powder,  deposits  its 
duplex  layer  day  after  day,  and  finally  masses  of  immense  thickness  are 
thus  piled  up,  which,  by  preserving  the  alternations  of  sand  and  mica, 
tell  the  tale  of  their  formation.  I  do  not  wish  you  to  accept  this  with- 
out proof.  Take  the  sand  and  mica,  mix  them  together  in  water,  and 
allow  them  to  subside,  they  will  arrange  themselves  in  the  manner  I 

*  I  merely  use  this  as  an  illustration ;  the  deposition  may  have  really  been  due 
to  sediment  carried  down  by  rivers.  But  the  action  must  have  been  periodic, 
and  the  powder  duplex. 


432  APPENDIX. 

have  indicated  ;  and  by  repeating  the  process  you  can  actually  build  up 
a  sandstone  mass  which  shall  be  the  exact  counterpart  of  that  presented 
by  nature,  as  I  have  done  in  this  glass  jar.  Now  this  structure  cleaves 
with  readiness  along  the  planes  in  which  the  particles  of  mica  are 
strewn.  Here  is  a  mass  of  such  a  rock  sent  to  me  from  Halifax  :  here 
are  other  masses  from  the  quarries  of  Over  Darwen  in  Lancashire. 
With  a  hammer  and  chisel  you  see  I  can  cleave  them  into  flags ;  indeed 
these  flags  are  made  use  of  for  roofing  purposes  in  the  districts  from 
which  the  specimens  have  come,  and  receive  the  name  of  "  slate-stone." 
But  you  will  discern,  without  a  word  from  me,  that  this  cleavage  is  not 
a  crystalline  cleavage  any  more  than  that  of  a  hayrick  is.  It  is  not  an 
arrangement  produced  by  molecular  forces ;  indeed  it  would  be  just  as 
reasonable  to  suppose  that  on  this  jar  of  sand  and  mica  the  particles 
arranged  themselves  into  layers  by  the  forces  of  crystallization,  instead 
of  by  the  simple  force  of  gravity,  as  to  imagine  that  such  a  cleavage 
as  this  could  be  the  product  of  crystallization. 

This,  so  far  as  I  am  aware  of,  has  never  been  imagined,  and  it  has 
been  agreed  among  geologists  not  to  call  such  splitting  as  this  cleavage 
at  all,  but  to  restrict  the  term  to  a  class  of  phenomena  which  I  shall 
now  proceed  to  consider. 

Those  who  have  visited  the  slate  quarries  of  Cumberland  and  North 
Wales  will  have  witnessed  the  phenomena  to  which  I  refer.  We  have 
long  drawn  our  supply  of  roofing-slates  from  such  quarries ;  schoolboys 
ciphered  on  these  slates,  they  were  used  for  tombstones  in  churchyards, 
and  for  billiard-tables  in  the  metropolis  ;  but  not  until  a  comparatively 
late  period  did  men  begin  to  inquire  how  their  wonderful  structure  was 
produced.  What  is  the  agency  which  enables  us  to  split  Honister 
Crag,  or  the  cliffs  of  Snowdon,  into  laminae  from  crown  to  base  V  This 
question  is  at  the  present  moment  one  of  the  greatest  difficulties  of 
geologists,  and  occupies  their  attention,  perhaps,  more  than  any  other. 
You  may  wonder  at  this.  Looking  into  the  quarry  of  Penrhyn,  you 
may  be  disposed  to  explain  the  question  as  I  heard  it  explained  two 
years  ago.  "•  These  planes  of  cleavage,"  said  a  friend  who  stood  beside 
me  on  the  quarry's  edge,  "  are  the  planes  of  stratification  which  have 
been  lifted  by  some  convulsion  into  an  almost  vertical  position."  But 
this  was  a  great  mistake,  and  indeed  here  lies  the  grand  difficulty  of 
the  problem.  These  planes  of  cleavage  stand  in  most  cases  at  a  high 
angle  to  the  bedding.  Thanks  to  Sir  Roderick  Murchison,  who  has 
kindly  permitted  me  the  use  of  specimens  from  the  Museum  of  Practical 
Geology  (and  here  I  may  be  permitted  to  express  my  acknowledgments 
to  the  distinguished  staff  of  that  noble  establishment,  who,  instead  of 
considering  me  an  intruder,  have  welcomed  me  as  a  brother),  I  am  able 


APPENDIX.  433 

to  place  the  proof  of  this  before  you.  Here  is  a  mass  of  slate  in  which 
the  planes  of  bedding  are  distinctly  marked ;  here  are  the  planes  of 
cleavage,  and  you  see  that  one  of  them  makes  a  large  angle  with  the 
other.  The  cleavage  of  slates  is  therefore  not  a  question  of  stratifica- 
tion, and  the  problem  which  we  have  now  to  consider  is,  "  By  what 
cause  has  this  cleavage  been  produced  ?  " 

In  an  able  and  elaborate  essay  on  this  subject,  in  1835,  Professor 
Sedgwick  proposed  the  theory  that  cleavage  is  produced  by  the  action 
of  crystalline  or  polar  forces  after  the  mass  has  been  consolidated.  "  We 
may  affirm,"  he  says,  "  that  no  retreat  of  the  parts,  no  contraction  of 
dimensions  in  passing  to  a  solid  state,  can  explain  such  phenomena. 
They  appear  to  me  only  resolvable  on  the  supposition  that  crystalline 
or  polar  forces  acted  upon  the  whole  mass  simultaneously  in  one 
direction  and  with  adequate  force."  And  again,  in  another  place: 
"  Crystalline  forces  have  rearranged  whole  mountain-masses,  producing 
a  beautiful  crystalline  cleavage,  passing  alike  through  all  the  strata."* 
The  utterance  of  such  a  man  struck  deep,  as  was  natural,  into  the 
minds  of  geologists,  and  at  the  present  day  there  are  few  who  do  not 
entertain  this  view  either  in  whole  or  in  partf  The  magnificence  of 
the  theory,  indeed,  has  in  some  cases  caused  speculation  to  run  riot, 
and  we  have  books  published,  aye,  and  largely  sold,  on  the  action  of 
polar  forces  and  geologic  magnetism,  which  rather  astonish  those  who 
know  something  about  the  subject.  According  to  the  theory  referred 
to,  miles  and  miles  of  the  districts  of  North  Wales  and  Cumberland, 
comprising  huge  mountain-masses,  are  neither  more  nor  less  than  the 
parts  of  a  gigantic  crystal.  These  masses  of  slate  were  originally  fine 
mud ;  this  mud  is  composed  of  the  broken  and  abraded  particles  of  older 
rocks.  It  contains  silica,  alumina,  iron,  potash,  soda,  and  mica,  mixed 
in  sensible  masses  mechanically  together.  In  the  course  of  ages  the 
mass  became  consolidated,  and  the  theory  before  us  assumes  that  after- 
wards a  process  of  crystallization  rearranged  the  particles  and  developed 
in  the  mass  a  single  plane  of  crystalline  cleavage.  With  reference  to 
this  hypothesis,  I  will  only  say  that  it  is  a  bold  stretch  of  analogies  ;  but 

*  "  Transactions  of  the  Geological  Society,"  Ser.  ii.  vol.  iii.  p.  477. 

t  In  a  letter  to  Sir  Charles  Lyell,  dated  from  the  Cape  of  Good  Hope,  February 
20, 1836,  Sir  John  Herschel  writes  as  follows:  "If  rocks  have  been  so  heated  as 
to  allow  of  a  commencement  of  crystallization,  that  is  to  say,  if  they  have  been 
heated  to  a  point  at  which  the  particles  can  begin  to  move  amongst  themselves, 
or  at  least  on  their  own  axes,  some  general  law  must  then  determine  the  position 
in  which  these  particles  will  rest  on  cooling.  Probably  that  position  will  have 
some  relation  to  the  direction  in  which  the  heat  escapes.  Now  when  all  or  a 
majority  of  particles  of  the  same  nature  have  a  general  tendency  to  one  position, 
that  must  of  course  determine  a  cleavage  plane." 


434  APPENDIX. 

still  it  has  done  good  service :  it  has  drawn  attention  to  the  question ; 
right  or  wrong,  a  theory  thus  thoughtfully  uttered  has  its  value ;  it  is 
a  dynamic  power,  which  operates  against  intellectual  stagnation ;  and, 
even  by  provoking  opposition,  is  eventually  of  service  to  the  cause  of 
truth.  It  would,  however,  have  been  remarkable,  if,  among  the  ranks 
of  geologists  themselves,  men  were  not  found  to  seek  an  explanation  of 
the  phenomena  in  question,  which  involved  a  less  hardy  spring  on  the 
part  of  the  speculative  faculty  than  the  view  to  which  I  have  just 
referred. 

The  first  step  in  an  inquiry  of  this  kind  is  to  put  oneself  into  contact 
with  nature,  to  seek  facts.  This  has  been  done,  and  the  labours  of 
Sharpe  (the  late  President  of  the  Geological  Society,  who,  to  the  loss 
of  science  and  the  sorrow  of  all  who  knew  him,  has  so  suddenly  been 
taken  away  from  us),  Sorby,  and  others,  have  furnished  us  with  a  body 
of  evidence  which  reveals  to  us  certain  important  physical  phenom- 
ena, associated  with  the  appearance  of  slaty  cleavage,  if  they  have 
not  produced  it.  The  nature  of  this  evidence  we  will  now  proceed  to 
consider. 

Fossil  shells  are  found  in  these  slate-rocks.  I  have  here  several 
specimens  of  such  shells,  occupying  various  positions  with  regard  to  the 
cleavage  planes.  They  are  squeezed,  distorted,  and  crushed.  In  some 
cases  a  flattening  of  the  convex  shell  occurs,  in  others  the  valves  are 
pressed  by  a  force  which  acted  in  the  plane  of  their  junction,  but  in  all 
cases  the  distortion  is  such  as  leads  to  the  inference  that  the  rock 
which  contains  these  shells  has  been  subjected  to  enormous  pressure 
in  a  direction  at  right  angles  to  the  planes  of  cleavage  ;  the  shells  are 
all  flattened  and  spread  out  upon  these  planes.  I  hold  in  my  hand  a 
fossil  trilobite  of  normal  proportions.  Here  is  a  series  of  fossils  of  the 
same  creature  which  have  suffered  distortion.  Some  have  lain  across, 
some  along,  and  some  oblique  to  the  cleavage  of  the  slate  in  which  they 
are  found ;  in  all  cases  the  nature  of  the  distortion  is  such  as  required 
for  its  production  a  compressing  force  acting  at  right  angles  to  the 
planes  of  cleavage.  As  the  creatures  lay  in  the  mud  in  the  manner 
indicated,  the  jaws  of  a  gigantic  vice  appear  to  have  closed  upon  them 
and  squeezed  them  into  the  shape  you  see.  As  further  evidence  of  the 
exertion  of  pressure,  let  me  introduce  to  your  notice  a  case  of  con- 
tortion which  has  been  adduced  by  Mr.  Sorby.  The  bedding  of  the 
rock  shown  in  this  figure*  was  once  horizontal ;  at  A  we  have  a  deep 
layer  of  mud,  and  at  m  n  a  layer  of  comparatively  unyielding  gritty 
material ;  below  that  again,  at  B,  we  have  another  layer  of  the  fine 

*  Omitted  here. 


APPENDIX.  435 

mud  of  which  slates  are  formed.  This  mass  cleaves  along  the  shading 
lines  of  the  diagram  ;  but  look  at  the  shape  of  the  intermediate  bed  :  it 
is  contorted  into  a  serpentine  form,  and  leads  irresistibly  to  the  conclu- 
sion that  the  mass  has  been  pressed  together  at  right  angles  to  the 
planes  of  cleavage.  This  action  can  be  experimentally  imitated,  and  I 
have  here  a  piece  of  clay  in  which  this  is  done,  and  the  same  result  pro- 
duced on  a  small  scale.  The  amount  of  compression,  indeed,  might  be 
roughly  estimated  by  supposing  this  contorted  bed  m  n  to  be  stretched 
out,  its  length  measured  and  compared  with  the  distance  c  d ;  we  find 
in  this  way  that  the  yielding  of  the  mass  has  been  considerable. 

Let  me  now  direct  your  attention  to  another  proof  of  pressure.  You 
see  the  varying  colours  which  indicate  the  bedding  on  this  mass  of  slate. 
The  dark  portion,  as  I  have  stated,  is  gritty,  and  composed  of  compara- 
tively coarse  particles,  which,  owing  to  their  size,  shape,  and  gravity, 
sink  first  and  constitute  the  bottom  of  each  layer.  Gradually  from 
bottom  to  top  the  coarseness  diminishes,  and  near  the  upper  surface  of 
each  layer  we  have  a  mass  of  comparatively  fine  clean  mud.  Some- 
times this  fine  mud  forms  distinct  layers  in  a  mass  of  slate-rock,  and  it 
is  the  mud  thus  consolidated  from  which  are  derived  the  German  razor- 
stones,  so  much  prized  for  the  sharpening  of  surgical  instruments.  I 
have  here  an  example  of  such  a  stone.  When  a  bed  is  thin,  the  clean 
white  mud  is  permitted  to  rest,  as  in  this  case,  upon  a  slab  of  the 
coarser  slate  in  contact  with  it :  when  the  bed  is  thick,  it  is  cut  into 
slices  which  are  cemented  to  pieces  of  ordinary  slate,  and  thus  rendered 
stronger.  The  mud  thus  deposited  sometimes  in  layers  is,  as  might  be 
expected,  often  rolled  up  into  nodular  masses,  carried  forward,  and  de- 
posited by  the  rivers  from  which  the  slate-mud  has  subsided.  Here, 
indeed,  are  such  nodules  enclosed  in  sandstone.  Everybody  who  has 
ciphered  upon  a  school-slate  must  remember  the  whitish-green  spots 
which  sometimes  dotted  the  surface  of  the  slate  ;  he  will  remember  how 
his  slate-pencil  usually  slid  over  such  spots  as  if  they  were  greasy.  Now 
these  spots  are  composed  of  the  finer  mud,  and  they  could  not  on  ac- 
count of  their  fineness,  lite  the  pencil  like  the  surrounding  gritty 
portions  of  the  slate.  Here  is  a  beautiful  example  of  the  spots :  you 
observe  them  on  the  cleavage  surface  in  broad  patches;  but  if  this 
mass  has  been  compressed  at  right  angles  to  the  planes  of  cleavage, 
ought  we  to  expect  the  same  marks  when  we  look  at  the  edge  of  the 
slab  ?  The  nodules  will  be  flattened  by  such  pressure,  and  we  ought  to 
see  evidence  of  this  flattening  when  we  turn  the  slate  edgeways.  Here 
it  is.  The  section  of  a  nodule  is  a  sharp  ellipse  with  its  major  axis 
parallel  to  the  cleavage.  There  are  other  examples  of  the  same  nature 
on  the  table ;  I  have  made  excursions  to  the  quarries  of  Wales  and 


436  APPENDIX. 

Cumberland,  and  to  many  of  the  slate-yards  of  London,  but  the  same 
fact  invariably  appears,  and  thus  we  elevate  a  common  experience  of 
our  boyhood  into  evidence  of  the  highest  significance  as  regards  one  of 
the  most  important  problems  of  geology.  In  examining  the  magnetism 
of  these  slates,  I  was  led  to  infer  that  these  spots  would  contain  a  less 
amount  of  iron  than  the  surrounding  dark  slate.  The  analysis  was 
made  for  me  by  Mr.  Hambly,  in  the  laboratory  of  Dr.  Percy,  at  the 
School  of  Mines.  The  result,  which  is  stated  in  this  Table,  justifies  the 
conclusion  to  which  I  have  referred. 

Analysis  of  Slate. 
Purple  Slate.     Two  Analyses. 

1.  Percentage  of  iron      ....     5.85 

2.  ""....          6.13 

Mean 5.99 

Greenish  Slate. 

1.  Percentage  of  iron          .         .        .        3.24 

2.  "  "  ....     3.12 

Mean 3.18 

The  quantity  of  iron  in  the  dark  slate  immediately  adjacent  to  the 
greenish  spot  is,  according  to  these  analyses,  nearly  double  of  the 
quantity  contained  in  the  spot  itself.  This  is  about  the  proportion 
which  the  magnetic  experiments  suggested. 

Let  me  now  remind  you  that  the  facts  which  I  have  brought  before 
you  are  typical  facts, — each  is  the  representative  of  a  class.  We  have 
seen  shells  crushed ;  the  unhappy  trilobites  squeezed,  beds  contorted, 
nodules  of  greenish  marl  flattened  ;  and  all  these  sources  of  inde- 
pendent testimony  point  to  one  and  the  same  conclusion,  namely,  that 
slate-rocks  have  been  subjected  to  enormous  pressure  in  a  direction  at 
right  angles  to  the  planes  of  cleavage.* 

In  reference  to  Mr.  Sorby's  contorted  bed,  I  have  said,  that  by  sup- 
posing it  to  be  stretched  out  and  its  length  measured,  it  would  give  us 
an  idea  of  the  amount  of  yielding  of  the  mass  above  and  below  the  bed. 
Such  a  measurement,  however,  would  not  quite  give  the  amount  of 
yielding ;  and  here  I  would  beg  your  attention  to  a  point,  the  signifi- 

*  While  to  my  mind  the  evidence  in  proof  of  pressure  seems  perfectly  irre- 
sistible, I  by  no  means  assert  that  the  manner  in  which  I  stated  it  is  incapable  of 
modification.  All  that  I  deem  important  is  the  fact  that  pressure  has  been 
exerted ;  and  provided  this  remain  firm,  the  fate  of  any  minor  portion  of  the 
evidence  by  which  it  is  here  established  is  of  comparatively  little  moment. 


APPENDIX.  437 

cance  of  which  has,  so  far  as  I  am  aware  of,  hitherto  escaped  attention. 
I  hold  in  my  hand  a  specimen  of  slate,  with  its  bedding  marked  upon 
it ;  the  lower  portions  of  each  bed  are  composed  of  a  comparatively 
coarse,  gritty  material,  something  like  what  you  may  suppose  this  con- 
torted bed  to  be  composed  of.  Well,  I  find  that  the  cleavage  takes  a 
bend  in  crossing  these  gritty  portions,  and  that  the  tendency  of  these 
portions  is  to  cleave  more  at  right  angles  to  the  bedding.  Look  to  this 
diagram:  when  the  forces  commenced  to  act,  this  intermediate  bed, 
which  though  comparatively  unyielding  is  not  entirely  so,  suffered 
longitudinal  pressure ;  as  it  bent,  the  pressure  became  gradually  more 
lateral,  and  the  direction  of  its  cleavage  is  exactly  such  as  you  would 
infer  from  a  force  of  this  kind, — it  is  neither  quite  across  the  bed,  nor 
yet  in  the  same  direction  as  the  cleavage  of  the  slate  above  and  below 
it,  but  intermediate  between  both.  Supposing  the  cleavage  to  be  at 
right  angles  to  the  pressure,  this  is  the  direction  which  it  ought  to  take 
across  these  more  unyielding  strata. 

Thus  we  have  established  the  concurrence  of  the  phenomena  of 
cleavage  and  pressure  — that  they  accompany  each  other ;  but  the  ques- 
tion still  remains  :  Is  this  pressure  of  itself  sufficient  to  account  for  the 
cleavage  ?  A  single  geologist,  as  far  as  I  am  aware,  answers  boldly  in 
the  affirmative.  This  geologist  is  Sorby,  who  has  attacked  the  question 
in  the  true  spirit  of  a  physical  investigator.  You  remember  the  cleav- 
age of  the  flags  of  Halifax  and  Over  Darwen,  which  is  caused  by  the 
interposition  of  plates  of  mica  between  the  layers.  Mr.  Sorby  examines 
the  structure  of  slate-rock,  and  finds  plates  of  mica  to  be  a  constituent. 
He  asks  himself,  what  will  be  the  effect  of  pressure  upon  a  mass  con- 
taining such  plates  confusedly  mixed  up  in  it  ?  It  will  be,  he  argues  — 
and  he  argues  rightly  —  to  place  the  plates  with  their  flat  surfaces  more 
or  less  perpendicular  to  the  direction  in  which  the  pressure  is  exerted. 
He  takes  scales  of  the  oxide  of  iron,  mixes  them  with  a  fine  powder, 
and,  on  squeezing  the  mass  finds  that  the  tendency  of  the  scales  is  to 
set  themselves  at  right  angles  to  the  line  of  pressure.  Now  the  planes 
in  which  these  plates  arrange  themselves  will,  he  contends,  be  those 
along  which  the  mass  cleaves, 

I  could  show  you,  by  tests  of  a  totally  different  character  from  those 
applied  by  Mr.  Sorby,  how  true  his  conclusion  is,  that  the  effect  of 
pressure  on  elongated  particles  or  plates  will  be  such  as  he  describes  it. 
Nevertheless,  while  knowing-  this  fact,  and  admiring  the  ability  with 
which  Mr.  Sorby  has  treated  this  question,  I  cannot  accept  his  explana- 
tion of  slate-cleavage.  I  believe  that  even  if  these  plates  of  mica  were 
wholly  absent,  the  cleavage  of  slate-rocks  would  be  much  the  same  as  it 
is  at  present. 


438  APPENDIX. 

I  will  not  dwell  here  upon  minor  facts,  —  I  will  not  urge  that  the 
perfection  of  the  cleavage  bears  no  relation  to  the  quantity  of  mica 
present ;  but  I  will  come  at  once  to  a  case  which  to  my  mind  com- 
pletely upsets  the  notion  that  such  plates  are  a  necessary  element  in 
the  production  of  cleavage. 

Here  is  a  mass  of  pure  white  wax :  there  are  no  mica  particles  here  ; 
there  are  no  scales  of  iron,  or  anything  analogous  mixed  up  with  the 
mass.  Here  is  the  self-same  substance  submitted  to  pressure.  I  would 
invite  the  attention  of  the  eminent  geologists  whom  I  see  before  me  to 
the  structure  of  this  mass.  No  slate  ever  exhibited  so  clean  a  cleavage ; 
it  splits  into  laminae  of  surpassing  tenuity,  and  proves  at  a  single  stroke 
that  pressure  is  sufficient  to  produce  cleavage,  and  that  this  cleavage  is 
independent  of  the  intermixed  plates  of  mica  assumed  in  Mr.  Sorby's 
theory.  I  have  purposely  mixed  this  wax  with  elongated  particles,  and 
am  unable  to  say  at  the  present  moment  that  the  cleavage  is  sensibly 
affected  by  their  presence,  —  if  anything,  I  should  say  they  rather  im- 
pair its  fineness  and  clearness  than  promote  it. 

The  finer  the  slate  the  more  perfect  will  be  the  resemblance  of  its 
cleavage  to  that  of  the  wax.  Compare  the  surface  of  the  wax  with  the 
surface  of  this  slate  from  Borrodale  in  Cumberland.  You  have  pre- 
cisely the  same  features  in  both :  you  see  flakes  clinging  to  the  surfaces 
of  each,  which  h«¥e  been  partially  torn  away  by  the  cleavage  of  the 
mass ;  I  entertain  the  conviction  that  if  any  close  observer  compares 
these  two  effects,  he  will  be  led  to  the  conclusion  that  they  are  the 
product  of  a  common  cause.* 

But  you  will  ask,  how,  according  to  my  view,  does  pressure  produce 
this  remarkable  result  ?  This  may  be  stated  in  a  very  few  words. 

Nature  is  everywhere  imperfect !  The  eye  is  not  perfectly  achro- 
matic, the  colours  of  the  rose  and  tulip  are  not  pure  colours,  and  the 
freshest  air  of  our  hills  has  a  bit  of  poison  in  it.  In  like  manner  there 
is  no  such  thing  in  nature  as  a  body  of  perfectly  homogeneous  structure. 
I  break  this  clay  which  seems  so  intimately  mixed,  and  find  that  the 
fracture  presents  to  my  eyes  innumerable  surfaces  along  which  it  has 
given  way,  and  it  has  yielded  along  these  surfaces  because  in  them  the 
cohesion  of  the  mass  is  less  than  elsewhere.  I  break  this  marble,  and 
even  this  wax,  and  observe  the  same  result :  look  at  the  mud  at  the 
bottom  of  a  dried  pond ;  look  to  some  of  the  ungravelled  walks  in 

*  I  have  usually  softened  the  wax  by  warming  it,  kneaded  it  with  the  fingers, 
and  pressed  it  between  thick  plates  of  glass  previously  wetted.  At  the  ordinary 
summer  temperature  the  wax  is  soft,  and  tears  rather  than  cleaves ;  on  this 
account  I  cool  my  compressed  specimens  in  a  mixture  of  pounded  ice  and  salt, 
and  when  thus  cooled  they  split  beautifully. 


APPENDIX.  439 

Kensington  Gardens  on  drying  after  rain,  —  they  are  cracked  and  split, 
and,  other  circumstances  being  equal,  they  crack  and  split  where  the 
cohesion  of  the  mass  is  least.  Take  then  a  mass  of  partially  con- 
solidated mud.  Assuredly  such  a  mass  is  divided  and  subdivided  by 
surfaces  along  which  the  cohesion  is  comparatively  small.  Penetrate 
the  mass,  and  you  will  see  it  composed  of  numberless  irregular  nodules 
bounded  by  surfaces  of  weak  cohesion.  Figure  to  your  mind's  eye 
such  a  mass  subjected  to  pressure,  —  the  mass  yields  and  spreads  out  in 
the  direction  of  least  resistance ;  *  the  little  nodules  become  converted 
into  laminae,  separated  from  each  other  by  surfaces  of  weak  cohesion, 
and  the  infallible  result  will  be  that  such  a  mass  will  cleave  at  right 
angles  to  the  line  in  which  the  pressure  is  exerted. 

Further,  a  mass  of  dried  mud  is  full  of  cavities  and  'fissures.  If  you 
break  dried  pipe-clay  you  see  them  in  great  numbers,  and  there  are 
multitudes  of  them  so  small  that  you  cannot  see  them.  I  have  here  a 
piece  of  glass  in  which  a  bubble  was  enclosed ;  by  the  compression  of 
the  glass  the  bubble  is  flattened,  and  the  sides  of  the  bubble  approach 
each  other  so  closely  as  to  exhibit  the  colours  of  thin  plates.  A  similar 
flattening  of  the  cavities  must  take  place  in  squeezed  mud,  and  this  must 
materially  facilitate  the  cleavage  of  the  mass  in  the  direction  already 
indicated. 

Although  the  time  at  my  disposal  has  not  permitted  me  to  develop 
this  thought  as  far  as  I  could  wish,  yet  for  the  last  twelve  months  the 
subject  has  presented  itself  to  me  almost  daily  under  one  aspect  or 
another.  I  have  never  eaten  a  biscuit  during  this  period  in  which  an 
intellectual  joy  has  not  been  superadded  to  the  more  sensual  pleasure, 
for  I  have  remarked  in  all  such  cases  cleavage  developed  in  the  mass  by 
the  rolling-pin  of  the  pastry-cook  or  confectioner.  I  have  only  to  break 
these  cakes,  and  to  look  at  the  fracture,  to  see  the  laminated  structure 
of  the  mass  ;  nay,  I  have  the  means  of  pushing  the  analogy  further :  I 
have  here  some  slate  which  was  subjected  to  a  high  temperature  during 
the  conflagration  of  Mr.  Scott  Russell's  premises.  I  invite  you  to  com- 
pare this  structure  with  that  of  a  biscuit ;  air  or  vapour  within  the  mass 
has  caused  it  to  swell,  and  the  mechanical  structure  it  reveals  is  pre- 
cisely that  of  a  biscuit.  I  have  gone  a  little  into  the  mysteries  of  baking 
while  conducting  my  inquiries  on  this  subject,  and  have  received  much 
instruction  from  a  lady-friend  in  the  manufacture  of  puff-paste.  Here 
is  some  paste  baked  in  this  house  under  my  own  superintendence.  The 


#  It  is  scarcely  necessary  to  say  that  if  the  mass  were  squeezed  equally  in  all 
directions  no  laminated  structure  could  be  produced;  it  must  have  room  to  yield 
iu  a  lateral  direction. 


440  APPENDIX. 

cleavage  of  our  hills  is  accidental  cleavage,  but  this  is  cleavage  with 
intention.  The  volition  of  the  pastry-cook  has  entered  into  the  forma- 
tion of  the  mass,  and  it  has  been  his  aim  to  preserve  a  series  of  surfaces 
of  structural  weakness,  along  which  the  dough  divides  into  layers. 
Puff-paste  must  not  be  handled  too  much,  for  then  the  continuity  of  the 
surfaces  is  broken  ;  it  ought  to  be  rolled  on  a  cold  slab,  to  prevent 
the  butter  from  melting  and  diffusing  itself  through  the  mass,  thus 
rendering  it  more  homogeneous  and  less  liable  to  split.  This  is  the 
whole  philosophy  of  puff-paste  ;  it  is  a  grossly  exaggerated  case  of  slaty 
cleavage. 

As  time  passed  on,  cases  multiplied,  illustrating  the  influence  of 
pressure  in  producing  lamination.  Mr.  Warren  De  la  Rue  informs  me 
that  he  once  wished  to  obtain  white-lead  in  a  fine  granular  state,  and  to 
accomplish  this  he  first  compressed  the  mass :  the  mould  was  conical, 
and  permitted  the  mass  to  spread  a  little  laterally  under  the  pressure. 
The  lamination  was  as  perfect  as  that  of  slate,  and  quite  defeated  him 
in  his  effort  to  obtain  a  granular  powder.  Mr.  Brodie,  as  you  are 
aware,  has  recently  discovered  a  new  kind  of  graphite :  here  is  the  sub- 
stance in  powder,  of  exquisite  fineness.  This  powder  has  the  peculi- 
arity of  clinging  together  in  little  confederacies ;  it  cannot  be  shaken 
asunder  like  lycopodium ;  and  when  the  mass  is  squeezed,  these  groups 
of  particles  flatten,  and  a  perfect  cleavage  is  produced.  Mr.  Brodie 
himself  has  been  kind  enough  to  furnish  me  with  specimens  for  this 
evening's  lecture.  I  will  cleave  them  before  you :  you  see  they  split 
up  into  plates  which  are  perpendicular  to  the  line  in  which  the  pressure 
was  exerted.  This  testimony  is  all  the  more  valuable,  as  the  facts  were 
obtained  without  any  reference  whatever  to  the  question  of  cleavage. 

I  have  here  a  mass  of  that  singular  substance  Boghead  Cannel.  This 
was  once  a  mass  of  mud,  more  or  less  resembling  this  one,  which  I  have 
obtained  from  a  bog  in  Lancashire.  I  feel  some  hesitation  in  bringing 
this  substance  before  you,  for,  as  in  other  cases,  so  in  regard  to  Boghead 
Cannel,  science  —  not  science,  let  me  not  libel  it,  but  the  quibbling,  liti- 
gious, money-loving  portion  of  human  nature  speaking  through  the  mask 
of  science  —  has  so  contrived  to  split  hairs  as  to  render  the  qualities  of 
the  substance  somewhat  mythical.  I  shall  therefore  content  myself  with 
showing  you  how  it  cleaves,  and  with  expressing  my  conviction  that 
pressure  had  a  great  share  in  the  production  of  this  cleavage. 

The  principle  which  I  have  enunciated  is  so  simple  as  to  be  almost 
trivial ;  nevertheless,  it  embraces  not  only  the  cases  I  have  mentioned, 
but,  if  time  permitted,  I  think  I  could  show  you  that  it  takes  a  much 
wider  range.  When  iron  is  taken  from  the  puddling  furnace,  it  is  a 
more  or  less  spongy  mass  :  it  is  at  a  welding  heat,  and  at  this  tempera- 


APPENDIX.  441 

ture  is  submitted  to  the  process  of  rolling :  bright  smooth  bars  such  as 
this  are  the  result  of  this  rolling.  But  I  have  said  that  the  mass  is  more 
or  less  spongy  or  nodular,  and,  notwithstanding  the  high  heat,  these 
nodules  do  not  perfectly  incorporate  with  their  neighbours :  what  then  ? 
You  would  say  that  the  process  of  rolling  must  draw  the  nodules  into 
fibres  —  it  does  so ;  and  here  is  a  mass  acted  upon  by  dilute  sulphuric 
acid,  which  exhibits  in  a  striking  manner  this  fibrous  structure.  The 
experiment  was  made  by  my  friend  Dr.  Percy,  without  any  reference 
to  the  question  of  cleavage. 

Here  are  other  cases  of  fibrous  iron.  This  fibrous  structure  is  the  re- 
sult of  mechanical  treatment.  Break  a  mass  of  ordinary  iron  and  you 
have  a  granular  fracture ;  beat  the  mass,  you  elongate  these  granules, 
and  finally  render  the  mass  fibrous.  Here  are  pieces  of  rails  along 
which  the  wheels  of  locomotives* have  slided ;  the  granules  have  yielded 
and  become  plates;  they  exfoliate  or  come  off  in  leaves.  All  these 
effects  belong,  I  believe,  to  the  great  class  of  phenomena  of  which  slaty 
cleavage  forms  the  most  prominent  example.* 

Thus,  ladies  and  gentlemen,  we  have  reached  the  termination  of  our 
task.  I  commenced  by  exhibiting  to  you  some  of  the  phenomena  of 
crystallization.  I  have  placed  before  you  the  facts  which  are  found 
to  be  associated  with  the  cleavage  of  slate-rocks.  These  facts,  as  finely 
expressed  by  Helmholtz,  are  so  many  telescopes  to  our  spiritual  vision, 
by  which  we  can  see  backward  through  the  night  of  antiquity,  and 
discern  the  forces  which  have  been  in  operation  upon  the  earth's 
surface 

"  Ere  the  lion  roared, 
Or  the  eagle  soared." 

From  evidence  of  the  most  independent  and  trustworthy  character, 
we  come  to  the  conclusion  that  these  slaty  masses  have  been  subjected 
to  enormous  pressure,  and  by  the  sure  method  of  experiment  we  have 
shown  —  and  this  is  the  only  really  new  point  which  has  been  brought 
before  you  —  how  the  pressure  is.  sufficient  to  produce  the  cleavage. 
Expanding  our  field  of  view,  we  find  the  self-same  law,  whose  foot- 
steps we  trace  amid  the  crags  of  Wales  and  Cumberland,  stretching  its 
ubiquitous  fingers  into  the  domain  of  the  pastry-cook  and  iron-founder  ; 
nay,  a  wheel  cannot  roll  over  the  half-dried  mud  of  our  streets  without 

*  An  eminent  authority  informs  me  that  he  believes  these  surfaces  of  weak 
cohesion  to  be  due  to  the  interposition  of  films  of  graphite,  and  not  to  any  ten- 
dency of  the  iron  itself  to  become  fibrous :  this  of  course  does  not  in  any  way 
militate  against  the  theory  which  I  have  ventured  to  propose.  All  that  the 
theory  requires  is  surfaces  of  weak  cohesion,  however  produced,  and  a  change  of 
shape  of  such  surfaces  consequent  on  pressure  or  rolling. 


442  APPENDIX. 

revealing  to  us  more  or  less  of  the  features  of  this  law.  I  would  say, 
in  conclusion,  that  the  spirit  .in  which  this  problem  has  been  attacked 
by  geologists  indicates  the  dawning  of  a  new  day  for  their  science. 
The  great  intellects  who  have  laboured  at  geology,  and  who  have  raised 
it  to  its  present  pitch  of  grandeur,  were  compelled  to  deal  with  the  sub- 
ject in  mass ;  they  had  no  time  to  look  after  details.  But  the  desire  for 
more  exact  knowledge  is  increasing  ;  facts  are  flowing  in,  which,  while 
they  leave  untouched  the  intrinsic  wonders  of  geology,  are  gradually 
supplanting  by  solid  truths  the  uncertain  speculations  which  beset  the 
subject  in  its. infancy.  Geologists  now  aim  to  imitate,  as  far  as  possible, 
the  conditions  of  nature,  and  to  produce  her  results ;  they  are  approach- 
ing more  and  more  to  the  domain  of  physics ;  and  I  trust  the  day  will 
soon  come  when  we  shall  interlace  our  friendly  arms  across  the  common 
boundary  of  our  sciences,  and  pursue  our  respective  tasks  in  a  spirit  of 
mutual  helpfulness,  encouragement,  and  good- will. 


INDEX. 


jEggischhorn,  100. 

Agassiz  on  glacier  motion,  270. 

Air-bubbles,  359. 

Aletsch  Glacier,  101. 

,  end  of,  120. 

Allelein  Glacier,  162. 

Alpine  travellers,  suggestions  to,  169. 

Alps,  winter  temperature  of,  168. 

Altmann's  theory  of  glacier  motion,  296. 

Arveiron,  arch  o'f,  217. 

Atmospheric  refraction,  35. 

Avalanche  at  Saas,  164. 

,  sound  of,  explained,  12, 14. 

Bakewell,  Mr.,  on  motion  of  Glacier 

des  Bossons,  337. 
Balmat,  169,  188. 
Bedding,  lines  of,  391. 
Bergschrund,  322. 
Blower,  glacier,  87. 
Blue  colour  of  ice,  256. 

snow,  29,  132.  203. 

water,  33,  250,  258. 

Blue  veins,  381. 

Boiling-point,  influence  of  pressure  on, 

408. 

Bois,  Glacier  du,  40. 
Bre"vent,  ascent  of,  172. 
Brocken,  Spirit  of  the,  22,  235. 
Bubbles  in  ice,  44,  359. 
snow,  251. 

Capillaries  of  glacier,  335. 
Cave  of  ice,  135. 
Cavities  in  ice,  356. 
Cells  in  ice,  147. 
Chamouni,  37. 

,  difficulties  at,  170. 

in  winter,  196. 

Charmoz,  view  from,  68. 
Charpentier's  theory  of  glacier  motion, 

296. 

Chemical  action,  rays  producing,  240. 
Chromatic  effects,  234. 


Cleavage,  406. 

caused  by  pressure,  6. 

,  contortions  of,  9. 

of  crystals    and  slate-rocks, 

lecture  on,  429. 

of  glaciers,  26. 

ice,  407. 


slate,  &c.,  1. 


Clouds,  iridescent,  105. 

on  Mont  Blanc,  82. 

on  Monte  Rosa,  124, 

,  winter,  at  Montanvert,  208. 


Colour  answers  to  pitch,  227. 
Colours  of  sky,  257. 

,  subjective,  37, 

Comet,  discovery  of,  186. 
Compass  affected,  140. 
Crepitation  of  glaciers,  357. 
Crevasses,  315. 

,  formation  of,  317. 

Crumples  in  ice,  415. 
Crystallization  of  ice,  353. 
Crystals,  cleavage  of,  3. 
of  snow,  130,  205,  212. 

Deafness,  artificial,  166. 
Differential  motion,  395. 

,  Dr.  Whewell  on, 


396. 

Diffraction,  explanation  of,  237. 
Dirt-bands,  45,  46,  68,  95,  367,  373. 

,  Forbes  on,  371. 

,  source  of,  369. 

Disks  in  ice,  planes  of,  358. 

Dolfuss,  M.,  hut  of,  18. 

Dome  du  Gout^,  75. 

Donny,  M.,  on  cohesion  of  liquids,  355. 

Echos,  theory  of,  15. 

Faraday,  Prof.,  on  Eegelation,  351. 
Faulberg,  cave  of,  107. 
Fee,  glacier  of,  165. 
Fend,  32. 


444 


INDEX. 


Finsteraarhorn,  104,  110. 

,  summit  of,  112. 

Flowers,  liquid,  in  ice,  354. 
Forbes,  Prof.,  comparison  of  glacier  to 
river,  306. 

-,  on  glacier  motion,  272, 


304,  308. 
145. 


379. 


-,  on  magnetism  of  rocks, 
-,  on  veined  structure, 
-,  viscous  theory,  311,  327, 


333,  335. 
Frost-bites,  191. 
Frozen  flowers,  130,  212. 
Furgge  Glacier,  160. 

Gases,  passage  of  heat  through,  243. 
Gebatsch  Alp,  23. 

,  glacier  of,  24,  26. 

Geneva,  Lake  of,  33,  258. 
Glaciers,  ancient,  action  of,  100. 

,  blower  on,  87. 

,  capillaries  of,  335. 

,  crepitation  of,  357. 

d'ecoulement,  301. 

de  Lechaud,  60. 

-,  motion  of,  286. 


420. 


286. 


-  du  Bois,  40. 

-  du  Ge"ant,  measurements  on, 

,    motion    of,    281, 


346. 


-  du  Talefre,  43. 

-,  groovings  on,  377. 
-,  measurement  of,  276. 

-  motion,  52,  269. 

,  pressure,    theory    of, 


origin  of,  248. 
— ,  reservoirs,  301. 
— ,  ridges  on,  42. 
— ,  structure  of,  148. 
— ,  tables  on,  44,  265. 
— ,  veins  of,  54. 

wrinkles  on,  370. 


Goethe's  theory  of  colours,  258. 
Corner  glacier,  120,  137. 

grat,  139,  145. 

Grand  Plateau,  187. 

Grands  Mulcts,  73, 185. 

Graun,  29. 

Grimsel,  the,  18,  99. 

Grindelwald,  glacier  of,  13. 

Grooving  on  glaciers,  377. 

Griiner's    theory    of    glacier    motion, 

296. 
Guides  of  Chamouni,  rules  of,  60, 170, 

192. 
Guyot,  M.,  on  veined  structure,  378. 


Hailstones,  conical,  31. 

,  spherical,  65. 

Handeck.  waterfall  of,  16. 
Heat  and  light,  223. 
work,  328. 

luminous,  240. 

mechanical  equivalent  of,  329. 

obscure,  240. 

passage  through  gases,  243. 

radiant,  105,  239. 

radiated,  242. 

specific,  334. 

Heisse  Platte,  the,  13. 
Hoch-joch,  32. 

Hochste  Spitze  of  Monte  Rosa,  128. 
Hopkins,  Mr.,  on  crevasses,  318. 
Hotel  de  Neufchatelois,  19. 
Hugi  on  glacier  motion,  270,  273. 
Huxley,   Mr.,   on    glacier    capillaries, 

338. 
Hydrogen,  effect  on  rays,  253. 

Ice,  blue  colour  of,  256. 

cascade,  94. 

cave,  135. 

cells,  147. 

cones,  266. 

,  crystallization  of,  353. 

,  effect  of  pressure  on,  409. 

,  experiments  on,  346. 

,  friability  of,  333. 

,  liquefaction  of,  353. 

,  liquid  flowers  in,  354. 

,  Thomson's  theory  of  plasticity  of, 

340. 

.  pressure  of,  405. 

,  softening  of,  333. 

,  structure  of,  136,  148. 

,  temperature  of,  241. 

,  white  seams  of,  56,  413. 

Interference  rings,  229. 

Jardin,  the,  61,  174. 
Joch,  the  passage  of  a,  28. 
Joule,  M.,  on  heat  and  work,  328. 
Jungfrau,  the,  11, 
,  evening  near,  106. 


Laminated  structure,  376. 
Lechaud,  glacier  de,  60. 

•,  motion  of,  286. 


Lenticular  structure,  381. 
Light  and  heat,  223. 

,  undulation  theory  of,  224. 

Linth,  M.  Escher  de  la",  271. 
Liquefaction  of  ice,  353,  408. 
Liquid  flowers  in  ice,  354. 

Magnetic  force,  144. 

Magnetism  of  rocks,  140,  143,  145. 

Marjelen  See,  101,  119. 


INDEX. 


445 


Mastic,  solution  of,  259. 

Mattmark  See,  162. 

Maximum  motion,  locus  of  point  of,  285. 

Mayenwand,  summit  of,  100. 

Measurement  of  glacier,  276. 

,  du  Ge"ant,  420. 

Mer  de  Glace,  42,  53, 173. 

,  motion  of,  275. 

,  winter  motion  of,  294. 

,  winter  visit  to,  195,  206. 

Meyer,  on  connexion  of  heat  with  work, 

Milk,  cause  of  blueness  of,  261. 
Mirage,  36. 
Montanvert,  40,  173. 

,  in  winter,  204. 

Mont  Blanc,  first  ascent  of,  68. 

,  second  ascent  of,  177,  189. 

,  summit  of,  81. 

Monte  Rosa,  first  ascent  of,  122. 

,  second  ascent  of,  151. 

,  summit  of,  128. 

Moraines,  263. 

,  of  Talefre,  63. 

Motion  of  glaciers,  52,  269. 
Moulins,  362. 

,  depth  of,  365. 

,  measurement  of,  364. 

Necker,  letter  from,  178. 
NeVe"  ice,  249,  251. 

Oberland,  expedition  to,  9. 
Oils,  effect  of  films  of,  236. 

Person,  M.,  on  softening  of  ice,  333. 
Pitch  of  musical  sounds,  225. 
Plasticity  of  ice,  Thomson's  theory  of, 

340. 

Polar  forces,  4. 
Pressure  and  liquefaction  of  ice,  408. 

veined  structure,  404. 

-,  effects  of,  on  boiling-point, 


408. 


cleavage,  26. 

ice,  489. 

theory  of  glacier  motion,  346. 


Radiant  heat,  105,  230. 
Rays,  calorific,  240. 

,  transmission  of,  242. 

Redness  of  sunset,  175. 

Refraction  on  Lake  of  Geneva,  35. 

Regelation,  347,  351. 

Reichenbach  fall,  17. 

Rendu,  comparison  of  glacier  to  river, 

306. 

,  measurements  of  glaciers,  304. 

,  notice  of  regelation,  301. 

on  conversion  of  snow  into  ice, 

301. 


Rendu  on  ductility.  298. 

on  law  of  circulation,  300. 

on  motion  of  glacier,  305. 

on  veined  structure,  301. 

,  theory  of  glaciers,  299. 

Rhone  at  Lake  of  Geneva,  34. 
Ridges  of  glacier,  42. 
Riffelhorn,  ascent  of,  133,  142. 
Rings,  interference,  220. 

round  sun,  21. 

Ripples  deduced  from  rings,  400. 
Ripple  theory,  Forbes  on,  398. 

of  veined  structure,  398. 


waves,  movement  of,  232. 


Rocks,  magnetism  of,  140,  143,  145. 

Saas,  avalanche  at,  164. 

Sabine,  Gen.,  on  veined  structure,  378. 

Sand-cones,  266. 

Saussure's  theory  of  glacier  motion,  296. 

Scheuchzer's  theory  of  glacier  motion, 

296. 

Seams,  white,  in  ice,  413. 
Sedgwick,  Prof.>  on  cleavage,  2. 
SeVacs,  51,  75. 
Serpentine,  boulders  of,  161. 
Shadows,  coloured,  38. 
Sharpe,  on  slaty  cleavage,  5. 
Silberhorn,  the,  11. 
Sky,  colours  of,  257. 
Slate,  cleavage  of,  1. 
Snow,  blue  colour  of,  29, 132,  203. 

crystals,  ISO,  205,  212. 

,  dry,  250. 

line,  248. 

,  perpetual,  248. 

,  sound  of  breaking,  202. 

storm,  sound  through,  215. 

,  whiteness  of,  explained,  250. 

Sorby,  Mr.,  on  slaty  cleavage,  5. 
Sound  in  a  vacuum,  224. 

,  intensity  of,  83. 

,  rate  of  motion  of,  226. 

Spectra,  interference,  178. 
Spectrum,  rays  of,  240. 
Stars,  twinkling  of,  72,  238. 
Stelvio,  pass  of,  29. 
Storm  on  Grands  Mulcts,  185. 

Mer  de  Glace,  210. 

Strahleck,  passage  of,  93,  97. 
Strata  of  ice,  136. 
Stratification  of  ne've',  392. 
slate,  1. 


Structure,  doubts  regarding,  92. 
of  ice,  136,148. 


Subjective  colours,  37. 
Summary  of  glacier  theory,  422. 
Sun,  rings  round,  21,  235. 
Sunrise  at  Chamouni,  39. 

•,  illumination  of  trees  at,  178. 


Sunset,  gorgeous,  184. 


446 


INDEX. 


Tacul,  motion  of  ice-wall  at,  289. 
Talefre,  glacier  of,  43,  62,  88. 

,  moraines  of,  62. 

Temperature,  winter,  of  Alps,  168. 
Theodolite,  use  of,  275. 
Theory  of  cleavage,  5. 
Thermometer  at  Jardin,  174. 

buried  on  Mont  Blanc,190. 

on  Finsteraarhorn,  113. 

Thomson,  Prof.,  theory  of  plasticity, 

340. 
regelation, 

352. 
Tyrol,  the,  23. 

Undulation  theory  of  light,  224. 
Unteraar,  glacier  of,  18. 

Vacuum  in  ice-cavities,  356. 

Veined  structure,  376,  383,  395,  404, 

408. 
,  experiments 'on,_382, 


Veined  structure,  Forbes  on,  379. 

,  Gen.  Sabine  on,  378 

,  M.  Guyot  on,  378. 

ripple  theory  of,  398. 


Viesch,  glacier  of,  118. 
Viscosity,  312,  325. 

Water  absorbs  red  rays,  254. 

,  blue  colour  of,  33, 250,  254,  258, 


261. 

,  rippling  waves  of,  232. 

Waves,  frozen,  43. 

,  interference  of,  231. 

motion,  Weber  on,  399. 

of  sound,  226. 


Wengern  Alp,  9. 
Wetterhorn,  echos  of,  15. 
White  ice,  seams  of,  56, 413. 
Winter  motion  of  Mer  de  Glace,  294. 
Wrinkles  on  glacier,  370. 

Young,  theory  of  light,  224. 


Cambridge  :  Printed  by  Welch,  Bigelow,  and  Company. 


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